Quadratics (20-2)

Question 1

Solve x² – 9 = 0

Answer 1

x = 3 or x = –3

Question 2

Solve x² + 5x + 6 = 0

Answer 2

x = –2 or x = –3

Question 3

Solve 2x² – 8 = 0

Answer 3

x = 2 or x = –2

Question 4

Factor x² + 7x + 12

Answer 4

(x + 3)(x + 4)

Question 5

Solve x² – 4x – 5 = 0

Answer 5

x = 5 or x = –1

Question 6

Solve 3x² + 12x = 0

Answer 6

x = 0 or x = –4

Question 7

Solve using quadratic formula: x² – 6x + 8 = 0

Answer 7

x = 2 or x = 4

Question 8

Graph y = x² – 4

Answer 8

Parabola, vertex at (0, –4)

Question 9

Solve x² + x – 6 = 0

Answer 9

x = 2 or x = –3

Question 10

Factor 2x² + 7x + 3

Answer 10

(2x + 1)(x + 3)

Question 11

Solve x² – 10x + 25 = 0

Answer 11

x = 5

Question 12

Solve 4x² – 9 = 0

Answer 12

x = 3/2 or x = –3/2

Question 13

Solve 3x² – 12x + 9 = 0

Answer 13

x = 1 or x = 3

Question 14

Graph y = –x² + 4x – 3

Answer 14

Parabola opens downward, vertex at (2,1)

Question 15

Solve x² + 4x + 3 = 0

Answer 15

x = –1 or x = –3

Question 16

Solve 5x² – 20x = 0

Answer 16

x = 0 or x = 4

Question 17

Solve x² – 8x + 15 = 0

Answer 17

x = 3 or x = 5

Question 18

Factor x² – x – 12

Answer 18

(x – 4)(x + 3)

Question 19

Solve using quadratic formula: 2x² + 3x – 2 = 0

Answer 19

x = 1/2 or x = –2

Question 20

Graph y = x² + 6x + 8

Answer 20

Parabola, vertex at (–3, –1)