Answer
$240$.
Work Step by Step
The given polynomial is
$= 19^2-11^2$
Use difference of two square pattern
$a^2-b^2=(a+b)(a-b)$.
We have $a=19$ and $b=11$.
$= (19+11)(19-11)$
Simplify.
$= (30)(8)$
Multiply.
$= 240$
Hence, the solution is $240$.