Trng THCS L Qun Bm Sn GV: Nguyn Th Vn cng n tp ton 8 i sI. L
thuyt:1) Hc thuc cc quy tc nhn,chia n thc vi n thc,n thc vi a
thc,php chia hai a thc 1 bin.2)Nmvngv vn dngc 7 hng ngthc- cc phng
php phn tch a thc thnh nhn t.3) Nu tnh cht c bn ca phn thc,cc quy
tc i du - quy tc rt gn phn thc,tm mu thc chung,quy ng mu thc.4) Hc
thuc cc quy tc: cng,tr,nhn,chia cc phn thc i s.5. Th no l hai phng
trnh tng ng? Cho v d.6. Hai quy tc bin i phng trnh.7. Phng trnh bc
nht mt n. Cch gii.8. Cch gii phng trnh a c v dng ax + b = 0.9. Phng
trnh tch. Cch gii.10. Cch gii phng trnh a c v dng phng trnh
tch.11Phng trnh cha n mu.12Cc bc gii bi ton bng cch lp phng
trnh.13Th no l hai bt phng trnh tng ng.14. Hai quy tc bin i bt phng
trnh.15. Bt phng trnh bc nht mt n.16. Cch gii phng trnh cha du gi
tr tuyt i.II. Bi tp: A.Mt s bi tp trc nghim 1) Chn biu thc ct A vi
mt biu thc ct B c ng thc ngCt A Ct B1/ 2x - 1 - x2 a) x2 - 92/ (x -
3)(x + 3) b) (x -1)(x2 + x + 1)3/ x3 + 1 c) x3 - 3x2 + 3x - 14/ (x
- 1)34/ (x - 1)3d) -(x - 1)24/ (x - 1)34/ (x - 1)3d) -(x - 1)2e) (x
+ 1)(x2 - x + 1) Cng n Tp Ton 8Trng THCS L Qun Bm Sn GV: Nguyn Th
Vn 2)Kt qu ca php tnh 2 2299 30112000 l:A. 1B. 10C. 100D. 10003)Phn
thc 1 84 83xxc rut gn :A. 142xB. 142 xD. 1 2 442+ + x x4) biu thc
32 xc gi tr nguyn th gi tr ca x lA. 1 B.1;2 C. 1;-2;4 D. 1;2;4;55)a
thc 2x - 1 - x2 c phn tch thnh A. (x-1)2B. -(x-1)2C. -(x+1)2D.
(-x-1)26)in biu thc thch hp vo trng trong cc biu thc sau :a/ x2 +
6xy + ..... = (x+3y)2b/
,_
+ y x21(..........) =883 3y x +c/ (8x3 + 1):(4x2 - 2x+ 1) =
............7)Tnh (x + 2y)2 ?A. x2 + x + 41B. x2 + 41C. x2 - 41D.
x2 - x + 418) Nghim ca phng trnh x3 - 4x = 0A. 0 B. 0;2 C. -2;2D.
0;-2;2B. Bi tp t lun:1/ Thc hin cc php tnh sau:a) (2x - y)(4x2 -
2xy + y2)b) (6x5y2 - 9x4y3 + 15x3y4): 3x3y2c) (2x3 - 21x2 + 67x -
60): (x - 5)d) (x4 + 2x3 +x - 25):(x2 +5)e) (27x3 - 8): (6x + 9x2 +
4)2/ Rt gn cc biu thc sau:a) (x + y)2 - (x - y)2b) (a + b)3 + (a -
b)3 - 2a3c) 98.28 - (184 - 1)(184 + 1)3/ Chng minh biu thc sau khng
ph thuc vo bin x,yA= (3x - 5)(2x + 11) - (2x + 3)(3x + 7)B = (2x +
3)(4x2 - 6x + 9) - 2(4x3 - 1) C = (x - 1)3 - (x + 1)3 + 6(x + 1)(x
- 1)4/ Phn tch cc a thc sau thnh nhn t: Cng n Tp Ton 8Trng THCS L
Qun Bm Sn GV: Nguyn Th Vn a) x2 - y2 - 2x + 2yb)2x + 2y - x2 - xyc)
3a2 - 6ab + 3b2 - 12c2 d)x2 - 25 + y2 + 2xye) a2 + 2ab + b2 - ac -
bc f)x2 - 2x - 4y2 - 4y g) x2y - x3 - 9y + 9xh)x2(x-1) + 16(1- x)n)
81x2 - 6yz - 9y2 - z2m)xz-yz-x2+2xy-y2p) x2 + 8x + 15 k) x2 - x -
12l) 81x2 + 45/ Tm x bit:a) 2x(x-5)-x(3+2x)=26b) 5x(x-1) = x-1c)
2(x+5) - x2-5x = 0 d) (2x-3)2-(x+5)2=0e) 3x3 - 48x = 0f) x3 + x2 -
4x = 46/ Chng minh rng biu thc:A = x(x - 6) + 10 lun lun dng vi mi
x.B = x2 - 2x + 9y2 - 6y + 37/ Tm gi tr nh nht ca biu thc A,B,C v
gi tr ln nht ca biu thc D,E:A = x2 - 4x + 1B = 4x2 + 4x + 11 C = (x
-1)(x + 3)(x + 2)(x + 6)D = 5 - 8x - x2 E = 4x - x2 +18/ Xc nh a a
thc: x3 + x2 + a - x chia ht cho(x + 1)29/ Cho cc phn thc sau:A = )
2 )( 3 (6 2 ++x xxB = 9 6922+ x xx C = x xx4 316 922D = 4 24 42++
+xx xE = 4222xx x F = 812 6 332+ +xx xa) Vi Iu kin no ca x th gi tr
ca cc phn thc trn xc nh.b)Tm x gi tr ca cc pthc trn bng 0.c)Rt gn
phn thc trn.10) Thc hin cc php tnh sau:a) 6 21++xx + x xx33 22++b)6
23+ x x xx6 262+c) y xx2 + y xx2 + + 2 244x yxyd) 2 31 x29 46 32
31xxx + 11/ Chng minh rng:52005 + 52003 chia ht cho 13b) a2 + b2 +
1 ab + a + bCho a + b + c = 0. chng minh: Cng n Tp Ton 8Trng THCS L
Qun Bm Sn GV: Nguyn Th Vn a3 + b3 + c3 = 3abc12/ a) Tm gi tr ca a,b
bit:a2 - 2a + 6b + b2 = -10b) Tnh gi tr ca biu thc; A =xz yyz xzy x
+++++nu01 1 1 + +z y x13/ Rt gn biu thc:A =1]1
+ +2 2 2 2121y x y xy x: 2 24x yxy14) Chng minh ng thc:1]1
,_
++ 1311232xxxx x: 12 1xxxx15 : Cho biu thc :
,_
,_
++ 122142212x x xxxAa) Rt gn A.b) Tnh gi tr ca biu thc A ti x
tho mn: 2x2 + x = 0c) Tm x A= 21d) Tm x nguyn A nguyn dng.16. Cho
biu thc :
,_
+ ,_
+311 :31349212x xxxxxBa) Rt gn B.b) Tnh gi tr ca biu thc B ti x
tho mn: 2x + 1= 5c) Tm x B = 53d) Tm x B < 0.17:Tm cc gi tr
nguyn ca x phn thc M c gi tr l mt s nguyn:3 25 7 102 xx xM18.Gii cc
phng trnh sau:a) 5 (x 6) = 4(3 2x) 35261 322 3 ) + ++xx xdb) 3
4x(25 2x) = 8x2 + x 3003176855 - 2x-x )+ ++x xe552 431 862 5 ) ++ x
x xc19.Gii cc phng trnh sau: Cng n Tp Ton 8Trng THCS L Qun Bm Sn
GV: Nguyn Th Vn a) 2x(x 3) + 5(x 3) = 0d) x2 5x + 6 = 0b) (x2 4) (x
2)(3 2x) = 0e) 2x3 + 6x2 = x2 + 3xc) (2x + 5)2 = (x + 2)220.Gii cc
phng trnh sau:) 2 )( 1 (15251 x1 )x x xa ++ 12131 - x1 )2 32+ +x
xxxxd242 52 2 x1 - x )xxxxb+ 16 81) 2 ( 218 458x7 )2++x x xxx xxe50
22510 255 x5 x )2 2 2+++xxx xxxc21.Gii cc phng trnh sau:a) x - 5=
3d) 3x - 1- x = 2b) - 5x= 3x 16e) 8 - x= x2 + xc) x - 4= -3x +
522.Gii cc bt phng trnh sau ri biu din tp nghim trn trc s:a) (x 3)2
< x2 5x + 4f) x2 4x + 3 0b) (x 3)(x + 3) (x + 2)2 + 3g) x3 2x2 +
3x 6 < 05735 - 4x )xc> 052 x ) +h41 435 3321 2x )+ ++ x xd 03
- x2 x ) k23.Chng minh rng:a) a2 + b2 2ab 0d) m2 + n2 + 2 2(m +
n)abbb +2a )2 2 41a1b) (a ) ,_
+ +be (vi a > 0, b > 0)c) a(a + 2) < (a + 1)224.Cho m
< n. Hy so snh:a) m + 5 v n + 5c) 3m + 1 v - 3n + 1b) - 8 + 2m v
- 8 + 2n 5 52m ) 2nvd25.Cho a > b. Hy chng minh:a) a + 2 > b
+ 2c) 3a + 5 > 3b + 2b) - 2a 5 < - 2b 5d) 2 4a < 3 4b Cng
n Tp Ton 8Trng THCS L Qun Bm Sn GV: Nguyn Th Vn 26.Lc 7 gi sng, mt
ngi i xe p khi hnh t A vi vn tc 10km/h. Sau lc 8 gi 40 pht, mt ngi
khc i xe my t A ui theo vi vn tc 30km/h. Hi hai ngi gp nhau lc my
gi.27.Hai ngi i b khi hnh hai a im cch nhau 4,18 km i ngc chiu nhau
gp nhau. Ngi th nht mi gi i c 5,7 km. Ngi th hai mi gi i c 6,3 km
nhng xut pht sau ngi th nht 4 pht. Hi ngi th hai i trong bao lu th
gp ngi th nht.28.Lc6gi, mttxut phttAnBvi vntctrungbnh 40km/h. Khi n
B, ngi li xe lm nhim v giao nhn hng trong 30 pht ri cho xe quay tr
v A vi vn tc trung bnh 30km/h. Tnh qung ng AB bit rng t v n A lc 10
gi cng ngy.29.Hai xe my khi hnh lc 7 gi sng t A n B. Xe my th nht
chy vi vn tc 30km/h, xe my th hai chy vi vn tc ln hn vn tc ca xe my
th nht l 6km/h. Trn ng i xe th hai dng li ngh 40 pht ri li tip tc
chy vi vn tc c. Tnh chiu di qung ng AB, bit c hai xe n B cng
lc.30.Mt can tun tra i xui dng t A n B ht 1 gi 20 pht v ngc dng t B
v A ht 2 gi. Tnh vn tc ring ca can, bit vn tc dng nc l 3km/h.31.Mt
t may o theo k hoch mi ngy phi may 30 o. Nh ci tin k thut, t may c
mi ngy 40 o nn hon thnh trc thi hn 3 ngy ngoi ra cn may thm c 20
chic o na. Tnh s o m t phi may theo k hoch.32.Hai cng nhn nu lm
chung th trong 12 gi s hon thnh cng vic. H lm chung trong 4 gi th
ngi th nht chuyn i lm vic khc, ngi th hai lm nt cng vic trong 10
gi. Hi ngi th hai lm mt mnh th bao lu hon thnh cng vic.33.Mt t sn
xut d nh hon thnh cng vic trong 10 ngy. Thi gian u, h lm mi ngy 120
sn phm. Sau khi lm c mt na s sn phm c giao, nh hp l ho mt s thao
tc, mingy h lm thm c 30 sn phm na so vi mi ngy trc . Tnh s sn phm m
t sn xut c giao.34.Hai t sn xut cng lm chung cng vic th hon thnh
trong 2 gi. Hi nu lm ring mt mnh th mi t phi ht bao nhiu thi gian
mi hon thnh cng vic, bit khi lm ring t 1 hon thnh sm hn t 2 l 3 gi.
Cng n Tp Ton 8Trng THCS L Qun Bm Sn GV: Nguyn Th Vn Hnh hcI. L
Thuyt1) nh ngha t gic,t gic li,tng cc gc ca t gic.2) Nu nh ngha,tnh
cht,du hiu nhn bit ca hnh thang,hnhthancn,
hnhthangvung,hnhchnht,hnh bnh hnh,hnh thoi, hnh vung .3) Cc nh l v
ng trung bnh ca tam gic,ca hnh thang.4) Nu nh ngha hai im i xng,hai
hnh i xng qua 1 ng thng; Hai imi xng,hai hnh i xng qua 1 im,hnh c
trc i xng,hnh c tm i xng.5) Tnh cht ca cc im cch u 1 ng thnh cho
trc.6) nh ngha a gic u,a gic li,vit cng thc tnh din tch ca: hnh ch
nht,hnh vung,tam gic,hnh thang,hnh bnh hnh,hnh thoi.7. nh l Talet,
nh l Talet o, h qu ca nh l Talet.8. Tnh cht ng phn gic ca tam
gic.9. Cc trng hp ng dng ca tam gic.10. Cc trng hp ng dng ca tam
gic vung.11Cngthctnhthtchcahnhhpchnht, dintchxung quanh v th tch ca
hnh lng tr ng, din tch xung quanh v th tch ca hnh chp u. Cng n Tp
Ton 8Trng THCS L Qun Bm Sn GV: Nguyn Th Vn II. Bi Tp:A. Mt s bi tp
trc nghim 1)Mt t gic l hnh vung nu n l :T gic c 3 gc vungHnh bnh
hnh c mt gc vungHnh thoi c mt gc vungHnh thang c hai gc vung2)Trong
cc hnh sau hnh no khng c trc i xng :A. Hnh thang cn B. Hnh bnh
hnhC. Hnh ch nht C. Hnh thoi3)Trong cc hnh sau hnh no khng c tm i
xng :A. Hnh thang cn B. Hnh bnh hnhC. Hnh ch nht C. Hnh thoi4)Cho
MNP vung ti M ; MN = 4cm ; NP = 5cm. Din tch MNP bng :A. 6cm2 B.
12cm2C. 15cm2D.20cm2 13)Hnh vung c -ng cho bng 4dm th cnh bng :A.
1dm B. 4dm C.8 dmD. 32dm5)Hnh thoi c hai ng cho bng 6cm v 8cm th
chu vi hnh thoi bng A. 20cmB. 48cm C. 28cmD. 24cm6)Hnh thang cn l
:A. Hnh thang c hai gc bng nhauB. Hnh thang c hai gc k mt y bng
nhauC. Hnh thang c hai cnh bn bng nhau B. BI TP T LUN1/ Cho hnh bnh
hnh ABCD c BC = 2AB v gc A = 600. Gi E,F theo th t l trung Im ca BC
v AD.T gic ECDF l hnh g?T gic ABED l hnh g? V sao ?Tnh s o ca gc
AED.2/ Cho ABC. Gi M,N ln lt l trung im ca BC,AC. Gi H l im i xng
ca N qua M.a) C/m t gic BNCHv ABHN l hbh.b) ABC tha mn iu kin g th
t gic BCNH l hnh ch nht.3/ Cho t gic ABCD. Gi O l giao im ca 2 ng
cho ( khng vung gc),I v K ln lt l trung im ca BC v CD. Gi M v N
theo th t l im i xng ca im O qua tm I v K. Cng n Tp Ton 8Trng THCS
L Qun Bm Sn GV: Nguyn Th Vn a) C/mrng t gic BMND l hnh bnh hnh.b)Vi
iukinnocahai ngchoACvBDthtgic BMND l hnh ch nht.c) Chng minh 3 im
M,C,N thng hng.4/ Cho hnh bnh hnh ABCD. Gi E v Fln lt l trung im ca
AD v BC. ng cho AC ct cc on thng BE v DF theo th t ti P v Q.a) C/m
t gic BEDF l hnh bnh hnh.b) Chng minh AP = PQ = QC.c) Gi R l trung
im ca BP. Chng minh t gic ARQE l hnh bnh hnh.5/ Cho t gic ABCD. Gi
M,N,P,Qln lt l trung imca AB,BC,CD,DA.a) T gic MNPQ l hnh g? V
sao?b)TmiukincatgicABCDtgicMNPQlhnh vung?c) Vi iu kin cu b) hy tnh
t s din tch ca t gic ABCD v MNPQ6/ Cho ABC,cc ng cao BH v CK ct
nhau ti E. Qua B k -ng thng Bx vung gc vi AB. Qua C k ng thng Cy
vung gc vi AC. Hai ng thng Bx v Cy ct nhau ti D.a) C/m t gic BDCE l
hnh bnh hnh.b) Gi M l trung im ca BC. Chng minh M cng l trung im ca
ED.c) ABC phi tha mn /kin g th DE i qua A7/ Cho hnh thang cn ABCD
(AB//CD),E l trung im ca AB.a) C/m EDC cn b) Gi I,K,M theo th t l
trung im ca BC,CD,DA. Tg EIKM l hnh g? V sao?c) Tnh S ABCD,SEIKM
bit EK = 4,IM = 6.8/ Cho hnh bnh hnh ABCD. E,F ln lt l trung im ca
AB v CD.a) T gic DEBF l hnh g? V sao?b) C/m 3 ng thng AC,BD,EF ng
qui.c) Gi giao im ca AC vi DE v BF theo th t l M v N. Chng minh t
gic EMFN l hnh bnh hnh.d) Tnh SEMFN khi bit AC = a,BC = b.9.Cho hnh
thang ABCD (AB//CD) ,mt ng thng song song vi 2 y, ct cc cnh AD,BC M
v N sao cho MD = 2MA.a.Tnh t s.b.Cho AB = 8cm, CD = 17cm.Tnh MN?
Cng n Tp Ton 8Trng THCS L Qun Bm Sn GV: Nguyn Th Vn 10.Cho hnh
thang ABCD(AB//CD).M l trung im ca CD.Gi I l giao im ca AM v BD, gi
K l giao im ca BM v AC.a.Chng minh IK // ABb.ng thng IK ct AD, BC
theo th t E v F.Chng minh: EI = IK = KF.11.Tam gic ABC c AB = 6cm,
AC = 12cm, BC = 9cm.Gi I l giao im ca cc ng phn gic , G l trng tm
ca tam gic.a.Chng minh: IG//BCb.Tnh di IG12.Cho hnh thoi ABCD.Qua C
k ng thng d ct cc tia i ca tia BA v CA theo th t E, F.Chng
minh:a.b.c. =1200( I l giaoim ca DE v BF)13..Cho tam gic ABC v cc
ng cao BD, CE.a,Chng minh: b.Tnh bit = 480.14.Cho tam gic ABC vung
A, ng cao AH, BC = 20cm, AH = 8cm.Gi D l hnh chiu ca H trn AC, E l
hnh chiu ca H trn AB.a.Chng minh tam gic ADE ng dng vi tam gic
ABC.b.Tnh din tch tam gic ADE15.Cho tam gic ABC vung A, AB = 15cm,
AC = 20cm, ng phn gic BD.a.Tnh di AD?b.Gi H l hnh chiu ca A trn BC.
Tnh di AH, HB?c.Chng minh tam gic AID l tam gic cn.16.Tam gic ABC
cn ti A, BC = 120cm, AB = 100cm.Cc ng cao AD v BE gp nhau H.a.Tm cc
tam gic ng dng vi tam gic BDH.b.Tnh di HD, BHc.Tnh di HE17.Cho tam
gic ABC, cc ng cao BD, CE ct nhau H.Gi K l hnh chiu ca H trn
BC.Chng minh rng: a.BH.BD = BK.BCb.CH.CE = CK.CB Cng n Tp Ton 8Trng
THCS L Qun Bm Sn GV: Nguyn Th Vn 18.Cho hnh thang cn MNPQ (MN //PQ,
MN < PQ), NP = 15cm, ng cao NI = 12cm, QI = 16 cm.a) Tnh IP.b)
Chng minh: QN NP.c) Tnh din tch hnh thang MNPQ.d) Gi E l trung im
ca PQ. ng thng vung gc vi EN ti N ct ng thng PQ ti K. Chng minh:
KN2 = KP . KQ19.Cho tam gic ABC vung to A; AB = 15cm, AC = 20cm, ng
cao AH.a) Chng minh: HBA ng dng vi ABC.b) Tnh BC, AH.c) Gi D l im i
xng vi B qua H. V hnh bnh hnh ADCE. T gic ABCE l hnh g? Ti sao?d)
Tnh AE.e) Tnh din tch t gic ABCE.20.Cho tam gic ABC vung ti A (AB
< AC), ng cao AH. T B k tia Bx AB, tia Bx ct tia AH ti K.a) T
gic ABKC l hnh g ? Ti sao?b) Chng minh: ABK ng dng vi CHA. T suy
ra: AB . AC = AK . CHc) Chng minh: AH2 = HB . HCd) Gi s BH = 9cm,
HC = 16cm. Tnh AB, AH.21.Cho tam gic ABC c ba gc nhn. ng cao AF, BE
ct nhau ti H. T A k tia Ax vung gc vi AC, t B k tia By vung gc vi
BC. Tia Ax v By ct nhau ti K.a) T gic AHBK l hnh g? Ti sao?b) Chng
minh: HAE ng dng vi HBF.c) Chng minh: CE . CA = CF . CBd) ABC cn
thm iu kin g t gic AHBK l hnh thoi.22.Cho tam gic ABC, AB = 4cm, AC
= 5cm. T trung im M ca AB v mt tia Mx ct AC ti N sao cho gcAMN =
gcACB.a) Chng minh: ABC ng dng vi ANM.b) Tnh NC.c) T C k mt ng thng
song song vi AB ct MN ti K. Tnh t s MKMN.23.Cho ABC c AB = 4cm, AC
= 5cm, BC = 6cm. Trn tia i ca tia AB ly im D sao cho AD = 5cm.a)
Chng minh: ABC ng dng vi CBD. Cng n Tp Ton 8Trng THCS L Qun Bm Sn
GV: Nguyn Th Vn b) Tnh CD.c) Chng minh: gcBAC = 2.gcACD24.Cho tam
gic vung ABC (gcA = 90o), ng cao AH. Bit BH = 4cm, CH = 9cm.a) Chng
minh: AB2 = BH . BCb) Tnh AB, AC.c) ng phn gic BD ct AH ti E (D
AC).Tnh DBAEBHSSv chng minh: DADCEHEA.25.Cho hnh bnh hnh ABCD. Trn
cnh BC ly im F. Tia AF ct BD v DC ln lt E v G. Chng minh:a) BEF ng
dng vi DEA. DGE ng dng vi BAE.b) AE2 = EF . EGc) BF . DG khng i khi
F thay i trn cnh BC.26.Cho ABC, v ng thng song song vi BC ct AB D v
ct AC E. Qua C k tia Cx song song vi AB ct DE G.a) Chng minh: ABC
ng dng vi CEG.b) Chng minh: DA . EG = DB . DEc) Gi H l giao im ca
AC v BG. Chng minh: HC2 = HE . HA27.Cho ABC cn ti A (gc A <
90o). Cc ng cao AD v CE ct nhau ti H.a) Chng minh: BEC ng dng vi
BDA.b) Chng minh: DHC ng dng vi DCA. T suy ra: DC2= DH . DAc) Cho
AB = 10cm, AE = 8cm. Tnh EC, HC.28.Quan st lng tr ng tam gic (hnh
1) ri in s thch hp vo trng trong bng sau:a (cm) 6 10b (cm) 3c (cm)
5 7h (cm) 8Chu vi y (cm)22Sxq (cm2) 88 Cng n Tp Ton 8ahbcHnh
1ACBA'B'C'Trng THCS L Qun Bm Sn GV: Nguyn Th Vn 29.Hnh lng tr ng
ABC.ABC c hai y ABC v ABC l cc tam gic vung ti A v A (hnh 2).Tnh
Sxq v th tch ca hnh lng tr. Bit: AB = 9cm, BC = 15cm, AA = 10cm. CU
HI N TPCHUNGCu 1:Tch cac nghiem cua phng trnh (4x 10 )(5x + 24) = 0
la:a) 24 b)- 24 c) 12d) 12Cau 2 : Mot phng trnh bac nhat mot an co
may nghiem:a) Vo nghiem b) Co vo so nghiemc) Luon co mot nghiem duy
nhat d) Co the vo nghiem , co the co mot nghiem duy nhat va cung co
the co vo so nghiem.Cau 3 :Cho x < y , cac bat ang thc nao sau
ay ung :a) x 5 < y 5b) 3x > 3y c) 2x 5 < 2y 5d) ca a,b,c
eu ung.Cau 4 : So nguyen x ln nhat thoa man bat phng trnh 2,5 +
0,3x < 0,5 la:a) 11b) 10c) 11d) mot so khacCau 5:Cho AB = 39dm ;
CD = 130cm. t so hai oan thang AB va CDla:a) 39130b) 13039c) 13d)
3Cau 6: Cho hnh lang tru ng ay tam giac co kch thc 3 cm, 4 cm, 5cm
va chieu cao 6 cm. The tch cua no la:a) 60 cm3b) 360 cm3c) 36 cm3d)
mot ap so khac.Cau 7: ien vao cho trong ( .)a) Hnh lap phng co canh
bang a. Dien tch toan phan cua no bang:. . . . . Cng n Tp Ton 8Hnh
2Trng THCS L Qun Bm Sn GV: Nguyn Th Vn b) Hnh hop ch nhat co ba kch
thc lan lt la3dm, 4dm, 50cm. The tch cua no bang:. . . .Cau 8: Bat
phng trnh nao di ay la bat phng trnh bac nhat mot an ?A.2x - 5 >
0 B.12- x+1 < 0 C. 3x + 3y > 0 D. 0.x + 5 < 0Cau 9: Cho
phng trnh ( 3x + 2k 5 ) ( 2x 1 ) = 0 co mot nghiem x = 1. Vay k = ?
:A. 1 B. 1 C. 0 D. 2Cau 10:Cho bat phng trrnh - 1 33 2x- B. 92x D.
29x>-Cau 11 : Tap nghiem cua bat phng trnh5 2x 0 la:A.5x/ x2 ' ;
B.5x/ x2 ' ; C. 5x/ x2 >' ; D.5x/ x2
