Rational Expressions 145
Step 2. Divide out common numerator and denominator factors.
=
()()
− ()()
⋅
()()+ ()()
()()+ ()()
(^2) ( ++
1 ( −−
)( −−
)( ++
++ ))((
++ ))((
Step 3. Multiply the remaining numerator factors to get the numerator of
the answer, and multiply the remaining denominator factors to get
the denominator of the answer.
=
−
=−
2
1
2
Step 4. Review the main results.
24
3
9
56
2
1
2
2
2
x
x
x
− xx 5
⋅
−
+ 55
=
()()xx 22
− 1 ()()xx 33
⋅
()()xx+ 333 ()()xx 33
()()xx+ 222 ()()xx 33
=−
Dividing Algebraic Fractions
To divide algebraic fractions, multiply the fi rst algebraic fraction by the
reciprocal of the second algebraic fraction (the divisor).
Problem Find the quotient:
xx
xx
xx
x
2
2
2
2
21 x
6
32 x
− 4
÷
3 x
−
.
Solution
Step 1. Change the problem to multiplication by the reciprocal of the
divisor.
xx
xx
xx
x
2
2
2
2
21 x
6
32 x
− 4
÷
3 x
−
=
−
⋅
xx −
xx
x
xx−
2
2
2
2
21 x+
6
4
32 x+
Step 2. Factor all numerators and denominators completely.