5a2-180
Factor 5 out of 5a2.
5(a2)-180
Factor 5 out of -180.
5a2+5⋅-36
Factor 5 out of 5a2+5⋅-36.
5(a2-36)
5(a2-36)
Rewrite 36 as 62.
5(a2-62)
Since both terms are perfect squares, factor using the difference of squares formula, a2-b2=(a+b)(a-b) where a=a and b=6.
5((a+6)(a-6))
Remove unnecessary parentheses.
5(a+6)(a-6)
5(a+6)(a-6)
Factor 5a^2-180