Question 207427
You are told the roots are -3 and 5
So you know that in order to be a root, that means the function equates to 0 at that value.
x = -3
x+3=0
x=5
x-5=0
Now mutliply those two terms to get the original equation. as follows:

{{{(x+3)(x-5)}}}
{{{x^2 -2x - 15}}}