10.4 Use Square roots to solve Quadratic Equations

x² = 16

• ± 4
• ± 8
• 4
• 8

Tags

CCSS.8.EE.A.2

3x² = 12

• ± 2
• 2
• ± √12
• ± 4

Tags

CCSS.8.EE.A.2

-5x² = -50

• ± 5
• ± 10
• ± √10
• -10

Tags

CCSS.8.EE.A.2

(x + 1) ² = 25

Remember to add the ± as soon as you take the square root of both sides, THEN move the one over to get x by itself.

• ± 5
• 4  or  -6
• -4  or  6
• ± 4

Tags

CCSS.HSA-REI.B.4B

(x - 2) ² = 9

• ± 3
• 5  or  -1
• -5  or  1
• ± 9

Tags

CCSS.HSA-REI.B.4B

Solve by taking square roots:
k² - 6 = 43

• k = √37
• k = 37 or - 37
• k = 7, k = -7
• no solution

Tags

CCSS.HSA-REI.B.4B

Solve

2y² - 5 = 93

Be careful, work from the outside in, get the squared term by itself, THEN take the square root.

• y = 7

• y = ±7

• y = 24.5

• y = ±24.5

Tags

CCSS.8.EE.A.2

-5x² = -50

• ± 5
• ± 10
• ± √10
• -10

Tags

CCSS.8.EE.A.2

Solve by taking square roots:
k² - 6 = 43

• k = √37
• k = 37 or - 37
• k = 7, k = -7
• no solution

Tags

CCSS.HSA-REI.B.4B

Solve by taking square roots: 5b² + 4 = -41

Hint: what do you do when you have a NEGATIVE square root?

• b = 9i, b = -9i

• b = 3i, b = -3i

• b = 9, b = -9

• b= 3, b= -3

Tags

CCSS.HSA-REI.B.4B