Question

ALGEBRA 2 help please! What is the simplified form of 4z^2-4z-15/2z^2+z-15?

A: 2z+3/z+3
B: 2z-3/z+3
C:2z+3/z-3
D:2z-3/z-3

Answer 1

well I'd factorise both quadratics then eliminate common factors

so start by factoring the numerator

I use this method for a difficult quadratic

\[ax^2 + bx + c = 0\]

start by multiplying a and c

so in your question its

4 x -15 = -60

what are the factors of -60 that add to -4, (hint the larger factor is negative)

Answer 2

so -10 and 6

Answer 3

@campbell_st

Answer 4

http://www.wolframalpha.com/input/?i=simplify%284z^2-4z-15%29%2F%282z^2%2Bz-15%29

Answer 5

\[
\frac{4 z^2-4 z-15}{2 z^2+z-15}=\frac{(2 z-5) (2 z+3)}{(z+3) (2 z-5)}=\frac{2 z+3}{z+3}

\]