Intermediate Algebra for College Students (7th Edition)

$-\text{ }\text{ }7$
The given expression can be written as: $=x^2-2(x)(7)+7^2$ RECALL: The perfect square trinomial $a^2-2ab+b^2$ can be factored as $(a-b)^2$. Factor the trinomial using the formula above with $a=x$ and $b=7$ to obtain: $=(x-7)^2$ Thus, the missing expression in the given statement is: $-\text{ }\text{ }7$