Solving by Taking the Square Roots

When solving a quadratic equation, when do you use the plus or minus (±) symbol?

• After taking the square root of both sides

• After adding the square to both sides

• After taking half of b

• After setting the equation equal to zero

2x²=100

• x = √25

• x = ±5√2

• x = √100

• x = ±√5

x² = 16

• ± 4

• ± 8

• 4

• 8

3x² = 12

• ± 2

• 2

• ± √12

• ± 4

x² + 4 = 68

• ± 8

• ± √8

• 8

• ± 64

Simplify

• ± 2 √5

• ± 4 √5

• ± 5 √2

• ± 5 √4

Solve using square roots.
5b² - 4 = 41

• b = 9, b = -9

• b = 3, b = -3

• b = 8, b = -8

• no solution