It is 16x2-24x+9
So...you can put it into the form a2+2ab+b2=(a+b)^2
if you see something in parentheses like this (4) to the zeroth power, then it equals 1. so, -7 is the answer because 1 - 8 is -7
To find the value of the interior angle, the equation is (n-2) 180n, where n is the number of sides.