Question

1) If you meant -13^2(5x+10)(x-3) (i.e. -169·(5x+10)(x-3)):
-169 ≠ 0, so zeros come from the factors (5x+10)=0 and (x-3)=0.
Solve 5x+10=0 → x = -2, and x-3=0 → x = 3.
So the zeros are x = -2 and x = 3.

how does that equal x=-2

Answer 1

You set the product equal to zero: -169(5x+10)(x-3)=0. Since -169 ≠ 0, the product is zero exactly when one of the factor factors is zero. For 5x+10=0:

5x + 10 = 0
5x = -10 (subtract 10 from both sides)
x = -10/5 (divide both sides by 5)
x = -2

So x = -2 is a root because it makes 5x+10 = 0 (and plugging in: 5(−2)+10 = −10+10 = 0).