5-5 Solving Quadratic Equations Objectives: Solve quadratic equations.
Solving a Quadratic 1. Set the equation equal to zero. 2. Factor it. 3. Set each factor equal to zero. 4. Get the variable by itself. 1. 2x 2 – 11x + 15 = 0 2. (2x – 5)(x – 3) = x-5=0 x-3=0 4. 2x = 5 x = 3 x =, 3 2x x =
Zero Product Property If ab = 0, then a = 0 or b = 0 example: If (x + 3)(x – 7) = 0, then (x + 3) = 0 or (x – 7) = 0
Class Work 5-5 Solve: 1) (x – 2)(x + 7) = 0 2) 4x(x + 8) = 0 3) 2x 2 + 5x = 12 4) 6x x = 10 5) 0 = x 2 – 11x ) x 2 = 18x – 81 7) 5x 2 – 180 = 0 8) 4x 2 – 25 = 0 9) 3x 2 = 24 10) x 2 – =