This is the order you need to use to solve this problem: PEMDAS
(Parentheses, Exponents, Multiplication, Division, Addition, Subtraction)
So you start with P and make your way down to S
(2x + 3)(x - 6) - 2x² + 3x + 30 First multiply (2x + 3)(x - 6) (distribute)
(2x)x - (2x)6 + (3)x - (3)6 = 2x² - 12x + 3x - 18 = 2x² - 9x - 18
(2x²- 9x - 18) - 2x² + 3x + 30 Simplify by combining like terms
-6x + 12