solve the following equation
Factoring.
1. x² - 4x - 21 = 0
2. x² = 8x - 15
3. 4x² = 32x -64
Extracting square root.
1. (x + 7)² = 3
2. (2x - 3)² = 8
Completing tge square.
1. x² - 6x + 9 = 25
2. x² - 2x -15 = 0
3. 4x² - 4x + 1 = 7
Using the quadratic formula.
1. x² - 2x -4 = 0
2. x² + 4x + 1 = 0​