### Home > CCA2 > Chapter 3 > Lesson 3.2.3 > Problem3-90

3-90.

Multiply or divide the expressions below. Simplify your results.

1. $\large \frac { x - 7 } { 9 ( 2 x - 1 ) } \div \frac { ( x + 5 ) ( x - 7 ) } { 6 x ( x + 5 ) }$

Take the reciprocal of (flip) the divisor (the fraction on the right side) and look for ones to factor out.

$\frac { 2 x } { 3 ( 2 x - 1 ) } = \frac { 2 x } { 6 x - 3 }$

1. $\large \frac { 6 x ^ { 2 } - x - 1 } { 3 x ^ { 2 } + 25 x + 8 } \cdot \frac { x ^ { 2 } + 4 x - 32 } { 2 x ^ { 2 } + 7 x - 4 }$

Factor each of the trinomials. (They all factor.) Look for ones to factor out. Multiply the factors that remain.

$\frac { x - 4 } { x + 4 }$