(5а-2)²= (p+a)²= (2+y)²= (x+5)²
(5а-2)²=25a^2 - 20a + 4 (p+a)²= p^2 +2pa + a^2 (2+y)²= 4 + 4y + y^2 (x+5)² = x^2 + 10x + 25