## Intermediate Algebra for College Students (7th Edition)

$(x-7)^2$
Given: $x^2-14x$ We need to add $(-7)^2$ to complete the square. Thus, $x^2+2x+(-7)^2=x^2+(-7)^2+(2)(x)(1)$ Apply difference of polynomial formula. or, $x^2+(-7)^2+(2)(x)(1)=(x-7)^2$