Quadratic Equations

Quadratic equation: yes or no?

100

x² - 3x + 9

Yes, it is a quadratic equation.

200

x - 2 = 7

No, it is not a quadratic equation

Extracting The Square Root

100

(x - 9)² = 121

x = -2 or x = 20

200

(8x - 1)(8x + 1)

x = ⅛ or x = -⅛

Factoring

100

48x² + 56x + 16 (use diamond method)

x = -½ or x = -⅔

200

x² - 17x = -30

x = 15 or x = 2

Completing The Square

100

x² - 8x - 42 = 0

x = 4 + √58 or 

x = 4 - √58

200

x² + 6x - 16 = 0

x = 2 or x = -8

Quadratic Formula

100

x² - 8x + 12

x = 6 or x = 2

200

(6x + 3)(x - 2)

x = 2 or x = -1/2