Chapter 4 Quadratic Functions and Factoring - 4.3 Solve x(squared) + bx + c = 0 - Guided Practice for Example 2 - Page 253: 6

$(y+8)^2$

Since the coefficient of the squared term is one, we know that the expression must factor to: $$ (y\pm a)(y\pm b)$$ Here, we see that a and b must multiply to get $64$ and add to get $16$. Thus, we find that the solution is: $$(y+8)(y+8)\\ (y+8)^2$$