help pretty please!!!

[dumbinmath]

(z^2+ 12z+36)/(z^2+ 13z + 42) ÷ (z^2+ 6z)/(z^2+ 5z-14)

okay i was going to factor it but i dont think thats right because i dont know how to factor the (z^2+ 6z) i know i have to flip the second equation around and multiply but when i do it it wont work..... what do i do?

 

[Loren]

First, learn to factor z[sup:2fhacuxm]2[/sup:2fhacuxm] + 6z by factoring out a common monomial factor, then follow your instinct --- factor and flip, etc.

 

[Denis]

Hint: ax^2 + bx = x(ax + b)