a2-81b2
Rewrite 81b2 as (9b)2.
a2-(9b)2
Since both terms are perfect squares, factor using the difference of squares formula, a2-b2=(a+b)(a-b) where a=a and b=9b.
(a+9b)(a-(9b))
Multiply 9 by -1.
(a+9b)(a-9b)
Factor a^2-81b^2
Solving MATH problems
We can solve all math problems. Get help on the web or with our math app