x(x + 4) = 396

x² + 4x = 396

x² + 4x – 396 = 0

(x + 22) (x – 18) = 0

x + 22 = 0 x – 18 = 0

x = -22 x = 18

x² + 5x = 0

x(x + 5) = 0

x = 0 x + 5 = 0

x = 0 x = -5

x² - 7x = 0

x(x – 7) = 0

x = 0 x – 7 = 0

x = 0 x = 7

3x² - 48 = 0

x² - 16 = 0

x² + 0x - 16 = 0

(x + 4) (x – 4) = 0

x + 4 = 0 x – 4 = 0

x = - 4 x = 4

5x² - 75 = 0

x² - 15 = 0

x² + 0x - 15 = 0

(x + 3.87) (x – 3.87) = 0

x + 3.87 = 0 x – 3.87 = 0

x = -3.87 x = 3.87

x(x + 5) = 150

x² + 5x = 150

x² + 5x – 150 = 0

(x + 15) (x – 10) = 0

x + 15 = 0 x – 10 = 0

x = -15 x = 10

x² + 3x – 1 = 0

a = 1

b = 3

c = -1

x = -b b² - 4ac

2a

x = -3 3² - 4(1)(-1)

2(1)

+–

+–

x = -3 9 + 4

2

+–

x = -3 13

2

+–

x = -3 3.6

2

+–

x = -3 + 3.6

2

x = 0.6

2

x = 0.3

x = -3 - 3.6

2

x = -6.6

2

x = -3.3

y² + 3y – 1 = 0

a = 1

b = 3

c = -1

y = -b b² - 4ac

2a

y = -3 3² - 4(1)(-1)

2(1)

+–

+–

y = -3 9 + 4

2

+–

y = -3 13

2

+–

y = -3 3.6

2

+–

y = -3 + 3.6

2

y = 0.6

2

y = 0.3

y = -3 - 3.6

2

y = -6.6

2

y = -3.3

4x² - 25 = 0

(2x + 5) (2x – 5 ) = 0

2x + 5 = 0 2x – 5 = 0

2x = -5 2x = 5

x = -5 x = 5

2 2

x = -2.5 x = 2.5

9y² - 16 = 0

(3y + 4) (3y – 4 ) = 0

3y + 4 = 0 3y – 4 = 0

3y = -4 3y = 4

y = -4 y = 4

3 3

y = -1.33 y = 1.33

3(x – 6)² = 108

3(x – 6)(x – 6) = 108

(x – 6)(x – 6) = 108

3

(x – 6)(x – 6) = 36

x² - 6x - 6x + 36 = 36

x² - 12x + 36 = 36

x² - 12x + 36 – 36 = 0

x² - 12x = 0

x(x – 12)=0

x = 0 x – 12 = 0

x = 0 x = 12

3(x + 2)(x + 3) = 60

(x + 2)(x + 3) = 60

3

(x + 2)(x + 3) = 20

x² + 3x + 2x + 6 = 20

x² + 5x + 6 = 20

x² + 5x + 6 – 20 = 0

x² + 5x - 14 = 0

(x + 7) (x – 2) = 0

x + 7 = 0 x – 2 = 0

x = -7 x = 2