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5/22/2018 Ecuaciones de Primer Grado
1/9
LICEO N1 JAVIERA CARRERA 2012 MATEMATICA Benjamn Rojas F.
ECUACIONES DE PRIMER GRADO
Una ecuacin es una igualdad que tiene un trmino desconocido llamado incgnita y que generalmen-
se simboliza con la letra x. Resolver una ecuacin es encontrar el valor de esa nica incgnita !ara esto de-bemos a!licar las !ro!iedades de una igualdad vistas anteriormente.
ecuaciones algebaicas" #e resuelven a!licando los conce!tos b$sicos del algebra.
%&em!lo" Resuelve las siguientes ecuaciones "
1' ( ) ( )1x2(2x( +=+
2' ( )[ ] ( )[ ](x21(1x211x) =++ (' ( ) ( ) x*1x(x
22=+
+' ( ) ( )2x+,1x)x2 +=+
)' ( ) ( ) ( )222
x2x+x2 =
,' ( )( ) ( )( )(x2,x1x22x ++=++
( ) ( ) ( )[ ] ( )[ ]
[ ] [ ]
10 x
10x
211(x,x2x))- x
x,(2x211x),2(x2(x
(x21(2x211x)2x2(,(x
(x21(1x211x)2'1x2(2x(1'
=
=
++=+=
+=++=
+=+++=+
=+++=+
( ) ( ) ( ) ( )
( )
1 x
((x x
),x+x)x2*x1x2xx, x
x+,)x)x2x*1x2xx, x
2x+,1x)x2+'x*1x(x'(
22
22
22
=
==
+=+=+++
+=+=+++
+=+=+
( ) ( ) ( ) ( ) ( ) ( ) ( )
( ) ( )
) xx
1,10x(,+x
1 /1,x10+(2,+1,x+xx1,
121)x)x+,x1,x+x+x(2x1,2x
1x1)2x2x)2x,+x1,x+x+x1,xx2
(x2,x1x22x,'x2x+x2')
222
22222
222
==
==
=+=++
+=+=++
++=+++=++
++=++=
ecuaciones con coe!icien"es !accionaios" #e resuelven calculando el entre todos los denominado-
res y multi!licando este valor !or todos los trminos de la ecua-cin de tal 3orma de eliminar los denominadores de la ecuacin.
4uego se resuelve la ecuacin que se obtiene como cualquier o-
tra ecuacin con coe3icientes enteros.
%&em!lo" Resuelve las siguientes ecuaciones"
1' x2(x =
2' ,x(
1
,
x
=+
('
(x)
,
1x2
(x +=
+
+'+
10x)
(x2
,
1x +=
5/22/2018 Ecuaciones de Primer Grado
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)' ( ) ( ) 1(x2(
11x2 =+
,' ( )12
1x
(
1x+
,
1)
+
(x21x( ++
=+
( ) ( ) ( )
x(x
,(*x,2x
1 /(,x**
(+ x1 /,x2
122*2+x+0x2+x(+*x,x(x
2+x+012x2+2*x2(,x, xx(, x
(x)1x212(x(,x,2xx(2((
x(
/*2
(x)
,
1x2
(x('/,,x
(
1
,
x2'x /(2
(
x'1
==
==
===
++=+==
+=++=+=
+=+=+=
+=
+
=+=
( ) ( )
( ) ( ) ( ) ( ) ( )
1*) x
2
( x1*)x
,+x1 /1*)x
,((x2,x120+,0x,x,+x
((x2,,x,0x,120x,++x
((x211x,10x,120(x2(1x+
/(1(x2(
11x2)'/2+
+
10x)
(x2
,
1x'+
=
==
==
=++=
=+++=+
=++=
=++
=
( )
( ) ( ) ( )
( x
,2x
(0(,1+x12x1,x,(,x
1x12+x1,(0x,(,(,x
1x121x++1)2(x2(1x(,
/12121x
(1x+
,1)
+(x21x(',
=
=
++=
++=++
++=+
++
=+
ecuaciones con inc#gni"a en el $eno%ina$o" #e utiliza el mismo mtodo usado !ara resolver una ecua-
cin 3raccionaria es decir encontrar el entre todos los
denominadores y multi!licar cada trmino de la ecuacin
!or este valor.
%&em!lo" Resuelve las siguientes ecuaciones"
1'(x2
*
(x
)
+
=
+
2'1x
(
1x
2
1x
12
=
+
('( ) 2x2
+
2x2
+
1x
12
=
+
+
+' 112x*x
1
(x
1x,
+x
)x*
2
=
+
+
)'12xx,
**x()x2
+x(
)x
(x2
*x,2
2
+
+=
+
+
,' 2)x)
1x+
+x+
2x(
(x(
(x2
2x2
x)=
++
+
2
5/22/2018 Ecuaciones de Primer Grado
3/9
( ) ( )
( ) ( ) ( ) ( )( ) ( )
( ) ( )
( ) ( ) ( ) ( )
(
+ x2 x
+(x,(x
1 /+(x1 /,(x
12(x2x1)21x*x10
(2x21x21x*1)x10
(1x21x1(x*(x2)
1x1x /1x1x
(
1x
2
1x
1
(x2
*(x2(x
(x
)(x2(x
1x
(
1x
2
1x
12'(x2(x /
(x2
*
(x
)'1
2
==
==
==
+==
=++=+
=++=+
+
+
=
++
++=
+
++
=
+
++
+
=
+
( )
( ) ( ) ( ) ( ) ( )
( ) ( ) ( )
( ) ( )
( ) ( ) ( ) ( )
( ) ( ) ( ) ( ) ( ) ( )
( )
2 x
(21,x
1+1)12x*x2)x1,
12x*x1+x2)x,1)x1,x*
12x*x1+x2)x,1)x1,x*
(x+x11x,+x)x*(x
(x+x /1(x+x
1
(x
1x,
+x
)x*
112x*x
1
(x
1x,
+x
)x*+'
(
) x
)(x
1 /)x(
212x+ x
2x22x+x21 x
1x21x2x21 x
1x1x21x21x
1x1x /1x2
+
1x2
+
1x
1
2x2
+
2x2
+
1x
1('
222
222
2
22
22
2
2
2
2
=
=
+++=++
+=+
+=+
=+
=
+
=
+
+
=
=
=
=
=+++
=+++
+=++
+
=
+
+
=
+
+
( ) ( ) ( ) ( )
( ) ( ) ( ) ( )
( )
) x
0x1
1)2**x()x1+x(
**x()x21)x1+x1,2x(x1
**x()x21)x1+x1,2x(x1
**x()x2)x(x2*x,+x(
+x((x2 /+x((x2
**x()x2
+x(
)x
(x2
*x,
12xx,
**x()x2
+x(
)x
(x2
*x,')
222
222
2
2
2
2
=
=
+=+
+=+
+=+
+=++
+
+
+=
+
+
+
+=
+
+
(
5/22/2018 Ecuaciones de Primer Grado
4/9
( ) ( ) ( ) ( ) ( )
( ) ( ) ( ) ( )
1(
102 x
1021(x
1 /1021(x
12(0,0120x120x+x+)x+01)0x
120x12012x+(0x+),0x+01)0x
1x1201x+122x(1)(x220x)(0
1x /,021x)
1x+
1x+
2x(
1x(
(x2
1x2
x)
2)x)
1x+
+x+
2x(
(x(
(x2
2x2
x)',
=
=
=
+=+
=+++
=+++
=
++
+
=
++
+
ecuaciones li"eales" #on ecuaciones en las que algunos o todos los coe3icientes numricos son letras se re-
suelven como cualquier ecuacin vista anteriormente.
%&em!lo" Resuelve las siguientes ecuaciones"
1' a2xa =+
2' +xb2xa =
(' a2
1
a
x1
a2
x2 =
+' ( ) ( )axbbabxa 22 ++=+
)' (2
(
ba2
x+=+
+
,' ( )
aa
b
b
xba
a
bxa 22=+
*' x(mxm 2 =+
' ( ) ( ) xa12x2axax ((((
+=++
'a
+x
+
ax =
10' 222bxa
ba
bxa
xa
bxa
bxa
=
+
( )
( )
( )
1 x
2a
2a x
2a2a x
2ax2xaba
2 x
ax22xa2ba xa
2ax
ax12xa+2xbxa2axa
/2aa2
1
a
x1
a2
x('+xb2xa2'a2xa1' 2
2
=
+
+=
+=+
+=+
=
=+=
=
===
=
==+
( ) ( ) ( )
( ) ( )
( ) ( )
( )
( )
ba2( xba x
b(a, x
ba
ba x
b(a,b,a21xbaba xb,a12(ba,xbababaxbxa
ba2,ba2(xbaxbbabaxa
ba2 /2(2
(
ba2
x+)'axbbabxa+'
2
2
22
22
22
+==
+=
=
+==
+=+++=
+=++++=+
+=+
+
++=+
+
5/22/2018 Ecuaciones de Primer Grado
5/9
( )
( ) ( )( ) ( )( )
( )( )
( )
( )
ba
2ab x
baa
ba2 x
(m xba2baxa
(m
(m(mxbbabbaxaxab
(m(m(m xbabxababxab
mx(xmbabxbabxab
x(mxm*'/abaa
b
b
xba
a
bxa',
2
2
(2(22
2(22(
22(22
222
+
=
+
=
==+
+
+=++=+
++=+=++
=+=+
=+=+
( ) ( )
( )
0 x
a12a(a(
0 x
0a12a(a(x
aaxa12xa(xa(
xa12x2axa(xa(xaxa(xa( x
xa12x2axax'
(22
(22
(((22
(((22((22(
((((
=
+
=
=+
+=+
+=+++++
+=++
( ) ( )
( )
( ) ( )
+a x
+a
+a+a x
1,a+a x
1,ax+xa
1,x+axa
+x+axa
/+aa
+x
+
ax'
2
2
2
+=
+=
=
=
=
=
=
( )( ) ( )( )
( ) ( )
( )
(a
ab x
(ab
abb x
abb(abx
1 /bab(abxbababxabx2
ababxxababx2xa
abbxaxabxa
bxabxa /bxabxa
ba
bxa
xa
bxa
bxa
bxa
ba
bxa
xa
bxa
bxa'10
2
2
2
22222
2
222
=
=
=
=
=
=+
=+
+
+
=
+
=
+
ecuaciones co%&ues"as" #e resuelven am!li3icando un lado de la igualdad o ambos lados !or el cal-
culado entre los denominadores de las 3racciones com!uestas con el !ro!sito de
trans3ormar la ecuacin en una ecuacin m$s sim!le.
%&em!lo" Resuelve las siguientes ecuaciones"
)
5/22/2018 Ecuaciones de Primer Grado
6/9
( )
( ) ( )
1)
)2 x
)21)x
1 /)2x1)
(,*2(0x1)x
*2x(0(,1)x
12x),12x)(
12x) /+
(
12x)
11
(
1).esy1)y)(resdenominadolosentreculado+
(
/1))
+x
(
1
/1)1)
11
(
-calel!or
)
+x
(
11)
11
3raccinlaam!li3icase*)0
)
+x
(
11)
11
('1
=
=
=
++=
=
=
=
=
=
( )
( ) ( )
,
(x
(,x
+x2x
x2x+
x21x,
2.esy+y2resdenominadolosx2 /
1
x2
x,
entrecalculadoel!or+
2
1
3raccinlaam!li3icase
1
x2
x,
(.esy(y1resdenominadolosentre/2+
/22
1
/((
x2(
/((
x2
calculadoel!or
(
x2(
(
x2
3raccinlaam!li3icase+
2
1
(
x2(
(
x2
'2
=
=
=
=+
=+
=
+
=
+
=
+
+
=
+
,
5/22/2018 Ecuaciones de Primer Grado
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( ) ( )( ) ( )
( )
( ) ( )
1 /(0)x2)0
22)0x1,0x0
0x1,022)x0
x1,10*)x(0(
x1, /((
10
x1,
*)x(0
(
10
x1,
*)x(0
(
10
x2+++0+0x
1()x0,0,0x
(
10
x22+1x+0
(x2+)1x,0
(,0.esy1)yentre,culado(
10
/(,01)
x2
1x
/(,0
(x2
,
1x
-calel!or
1)
x2
1x
(x2
,
1x
3raccinlaam!li3icase(
1(
1)
x2
1x
(x2
,
1x
'(
=
+=
+=
+=
+=
+
=
+
=
+
+
=
+
++
=
+
+
+
+
+
+
=
+
+
+
2)0
(0) x
(0)2)0x
=
=
( )
( )
2 x
21
x
2x1x
x
x.esyresdenominadolosentre2x1x
x
calculadoel!or
x
x11
13raccinlaam!li3icase2
/xx
x11
/x1
2
x
x11
1
x1esyresdenominadolosentre2
1x1
x11
1
calculadoel!or
x1
11
13raccinlaamli3icase2
x1 /x1
11
x1 /11
1
2
x1
1
1
11
1'+
=
=
=
=
+
+
=+
=+
+=
+
+
+
=
+
+
+
=
+
*
5/22/2018 Ecuaciones de Primer Grado
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( )
( )
( )
2
2
2
x
1
x1x
1x1
11x
x
.1xesyresdenominadolosentrex
1
1x /1x
x1
1x /11
1
1x
x
calculadoel!or
1x
x1
13raccinlaamli3icase
x
1
1x
x1
11
11x
x
')
=
+
=
+
=
+
( )
( )
( )
( )
( ) ( ) ( )
( )
( )
(
2 x
2(x
2x(x x
2x(x1 x
2x(x /x
x
1
2x(x
1
x
1
2x(x
1xx
.1xesyresdenominadolosentrex
1
x21x
1x1x
calculadoel!orx2
11x
x
3raccinlaam!li3icasex
1
1xx /2
1x /11x
x
x
1
x2
1
1x
x
x
1
1x1
11x
x
x
1
1x1
11x
x
x1
1
1x1
11x
x
22
22
22
22
22
2
2
2
2
2
2
=
=
+=
+=
+=
+
=
+
+
=
=
=
=
+
=
=
+
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