Question

Factor the following equations by product and sum. Then determine the solutions

Answer 1

Solution

Factor the following equations by product and sum.

Then determine the solutions

$a^2-121=0$

Step 1: Difference of two square

$\begin{gathered} a^2-121=0 \\ a^2-11^2=0 \\ (a-11)(a+11)=0 \end{gathered}$

Therefore the correct answer is

$(a-11)(a+11)$

Step 2: Then the solutions are

$\begin{gathered} a-11=0,a+11=0 \\ a=11,a=-11 \\ a=\pm11 \end{gathered}$