Question

find the product. simplify your answer
$(u - 1)(u + 1)$

Explanation:

Step1: Apply difference of squares rule

Recall that $(a-b)(a+b)=a^2-b^2$. Here $a=u$, $b=1$.

Step2: Substitute values into formula

$\boldsymbol{(u-1)(u+1)=u^2-1^2}$

Step3: Simplify the constant term

$1^2=1$, so $\boldsymbol{u^2-1^2=u^2-1}$

Answer:

$u^2 - 1$