Question

factor the expression.
$100 - 9m^{2}$
show your work here
$(10 + 3m)(10 - 3m)$
factor the expression.
$121n^{2}-4$
show your work here
$(11n + 5)(11n - 2)$
$(11n + 2)(13n - 2)$
$(22n + 5)(11n - 2)$
$(11n + 2)(11n - 2)$

Explanation:

Step1: Recall difference - of - squares formula

The difference - of - squares formula is $a^{2}-b^{2}=(a + b)(a - b)$.

Step2: Identify $a$ and $b$ for $121n^{2}-4$

For the expression $121n^{2}-4$, we have $a = 11n$ (since $(11n)^{2}=121n^{2}$) and $b = 2$ (since $2^{2}=4$).

Step3: Factor using the formula

Substitute $a = 11n$ and $b = 2$ into the difference - of - squares formula: $121n^{2}-4=(11n + 2)(11n - 2)$.

Answer:

$(11n + 2)(11n - 2)$