Solving Quadratic Equations Algebraically

Factoring

100

Identify the x-intercepts:

(x - 7)(x + 2) = 0

x = 7 x = -2

200

Factor and solve: 

x²+3x+2 = 0

x = -2 x = -1

300

Factor and solve: 

x² - 6x + 5 = 0

x = 5 x = 1

400

Factor and solve: 

x² - 6x = 27

x = 9 x = -3

500

Factor and solve: 

 2x² - 4x = 3 + x

x = -1/2 x = 3

Square Roots

100

x² = 4

x = 2 x = -2

200

 x² = 121

+11 or -11

300

4x² = -400

No solution/x-intercepts

400

x² -9 = -8

1 or -1

500

5x² + 3 = 128

x = 5 x = -5

Quadratic Formula

100

What is the quadratic formula?

x = -b +- sqrt(b² - 4ac) /(2a)

200

x² + 6x + 5 = 0

x = -1 x = -5

300

 x² - 9x = -20

x = 5 x = 4

400

2x² + 4 = -9x

x = -1/2 x = -4

500

 4x² = 15 + 17x 

x = 5 x = -3/4