Answer
$900$.
Work Step by Step
The given polynomial is
$= 78^2-72^2$
Use difference of two square pattern
$a^2-b^2=(a+b)(a-b)$.
We have $a=78$ and $b=72$.
$= (78+72)(78-72)$
Simplify.
$= (150)(6)$
Multiply.
$= 900$
Hence, the solution is $900$.
