Chapter 6 Rational Equations - Mr. Sjokvist · 2018. 9. 6. · Operations with rational expressions...

Chapter 6 Rational

Equations

Rational expressions

• These have a variable in the denominator Ex:

1/x

• We have to be careful of "non-permissible"

values. These are numbers that give an

undefined value.

Ex: state the non-

permissible value(s)

Ex: state the non-

permissible values (NPVs)

What should replace ?

State the operation to change

the 1st to the 2nd expression

Divide top and bottom by pq?

Simplify and state any NPVs

Simplify and state any NPVs

P. 317 q's 1-9, 18

Operations with rational

expressions

• Remember to watch for NPVs!

• Factor any polynomials first, then simplify

• When dividing, multiply by the reciprocal

Operations with rational

expressions

Ex:

simplify m

c

cf

fm

4

15

5

12 2

m

c

cf

fm

1

3

1

3 2

• First: cancel out common factors

• Next: cancel out or combine common variables

and write as a single fraction or term

0,,;9 mfcm

Ex: simplify & ID any NPVs

Ex: simplify & ID any NPVs

P. 327 q's 1-8,18

It's just a flesh wound

6.3 More operations

• Careful to make sure the denominators are

equal to add or subtract fractions!

• Continue to pay attention to NPVs

Ex: simplify

Ex: simplify

Ex: simplify

P. 336 q's 1-9, 20

Mini-quiz tomorrow (Venus day)

Quiz #4

48

358

3

58

22

4

xy

yx

xy

yx

358

48

3

58 2

2

4

yx

xy

xy

yx

1524

3244

333

58 2

2

4

yx

yx

yx

yx

Quiz #4

15

198

x

y

Quiz #5

)73)(73(

)73)(158(

xx

xx

6.4 Rational Equations • Can we use our rational skills to solve the

problem?

Ex: solve for f

1213 f 1f

Ex: solve

Ex: word problem

• Two hoses together fill a pool in 2h, but hose A

fills the pool in 3h. How long to fill the pool using

only hose B?

• Try writing a rational equation representing what

fractions of the pool are filled in one hour

P. 348 q's 1-7, 22

Chapter Review P. 352

odds

Practice Test P. 355

odds