Chapter 4 Quadratic Functions and Factoring - 4.3 Solve x(squared) + bx + c = 0 - Guided Practice for Example 2 - Page 253: 7

$(w-9)^2$

Since the coefficient of the squared term is one, we know that the expression must factor to: $$ (w\pm a)(w\pm b)$$ Here, we see that a and b must multiply to get $81$ and add to get $-18$. Thus, we find that the solution is: $$(w-9)(w-9)=(w-9)^2$$