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

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

campbell_st · Answer

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)

anonymous · Answer

so -10 and 6

anonymous · Answer

@campbell_st

anonymous · Answer

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

anonymous · Answer

$$
\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}

$$