Question

What value completes the square for the following? x^2 + 8x + __
A. 4
B. 8
C. 16
D. 32

Answer 1

lets think about this. we want to find a number that can make 2 numbers which add up to 8 and multiply out to the number we want to find. So in this case itd be 16. (x + 4)(x + 4). Foil that and you will see the rules 4 + 4 = 8 and 4 * 4 = 16

Answer 2

That is what I was thinking thanks!