Solving Quadratics Review

Method 1: Solve by taking square roots.

x² = 25

• x = 5 only

• x = 5 or x = -5

• x = 12.5 or -12.5

• x = 25 or x = -25

Tags

CCSS.HSA-REI.B.4B

Solve by taking square roots.

(x - 6)² = 16

• x = 4 or x = - 4

• x = 10 or x = -10

• x = 10 or x = 2

• x = 10 or x = - 2

Tags

CCSS.HSA-REI.B.4B

Which of the following will have "No Real Roots"?

• x² = -9

• x² = 9

• x² = 8

• (x - 5)² = 20

Tags

CCSS.HSA-REI.B.4B

(x + 7)² = -8

• x = 71 or x = -57

• x = 9.8 or x = -4.2

• x = 15 or x = -1

• No Real Roots. You can't take the square root of a negative number.

Tags

CCSS.HSA-REI.B.4B

Method 2: Using the quadratic formula.

When solving: x² + 8x + 6 = 0 by using the quadratic formula,

b²- 4ac =

• 88

• 40

• -8

• 8

Tags

CCSS.HSA-REI.B.4B

Using the quadratic formula.

When solving: x² - 3x - 2 = 0 by using the quadratic formula,

b²- 4ac =

• 1

• -1

• 11

• 17

Tags

CCSS.HSA-REI.B.4B

When using the quadratic formula (shown) to solve:

x² + 3x - 2 = 0 , the two answers will be:

• 
• 
• 
• 

Tags

CCSS.HSA-REI.B.4B

Method: Solving by Factoring and the zero product property.

Solve:

(x - 5)(x + 2) = 0

• x = 5 or x = 2

• x = -5 or x = 2

• x = 5 or x = -2

• x = 0

Tags

CCSS.HSA-REI.B.4B

Solve:

(3x - 15)(x + 7) = 0

• x = 15 x = -7

• x = -5 x = 7

• x = 3 x = 7

• x = 5 x = -7

Tags

CCSS.HSA-REI.B.4B

Solve by Factoring: DO NOT TRY TO DO IN YOUR HEAD.

x² + 3x - 18 = 0

• x = 3 x = -18

• x = -3 x = 18

• x = -6 x = - 3

• x = - 6 x = 3

Tags

CCSS.HSA-REI.B.4B