How do you simplify (9-z^2)/(2z^2+z-15)?

1 Answer
Jan 17, 2017

The answer is =(3-z)/(2z-5)

Explanation:

We use

a^2-b^2=(a+b)(a-b)

The numerator is

9-z^2=(3-z)(3+z)

The denominator is

2z^2+z-15=(2z-5)(z+3)

So,

(9-z^2)/(2z^2+z-15)=((3-z)cancel((3+z)))/((2z-5)cancel((z+3)))

=(3-z)/(2z-5)