The expression can be solved by expanding the bracket and multiplying out the terms


Therefore, the expression can be simplified as;

Alternatively, using the theorem of difference of two squares, which is

Hence,

Answer:
8%
Step-by-step explanation:
percent increase = [ (difference between initial value and final value) ÷ initial value] x 100
⇒ percent increase = [ (270 - 250) ÷ 250] x 100 = 8%