## Precalculus (6th Edition) Blitzer

$a^2-2ab+b^2$; minus; product of the first and second terms; plus
RECALL: $(a-b)^2=a^2-2ab+b^2.$ Thus, the missing expressions/words in the given statements are $a^2-2ab+b^2$; minus; product of the first and second terms; plus.