Question

x2+8x+16=0

Answer 1

You need to factor it out. You know that you can only get x^2 by multiplying x by x, so start with:

(x )(x ) = 0

16 could be 4 x 4 or 2 x 8 or 16 x 1. The only one of these that will get you 8x is 4 x 4 so:

(x + 4)(x + 4) = 0

Now you can solve...the only way this will equal zero is if one or both of the items in parentheses equals 0. Both are the same, so x has to equal -4.