what is the simplified form of 4z^2-16z+15/2z^2+z-15

Question

lalaly · Answer

$$\frac{4z^2-16z+15}{2z^2+z-15}$$ can u factorise these two polynomials?

anonymous · Answer

yes, i factored them to: (4z-15)(z-1)/(2z-15)(z+1)

lalaly · Answer

thats not right ... 
$$=\frac{(2z-5)(2z-3)}{(z+3)(2z-5)}$$

anonymous · Answer

but i thought the sum of the two numbers has to equal the middle number...

anonymous · Answer

Working together, it takes two computers  12 minutes to send out a company’s email. If it takes the slower computer 30 minutes to do the job on its own, how long will it take the faster computer to do the job on its own? 


Do not do any rounding.

lalaly · Answer

yeah thats only when the coeffecient of x^2 or z^2 =1

anonymous · Answer

what is it equal to here? and how would i find out?