solving radicals

Simplify the radical - 6√90

• 10√8

• 10√18

• 18√10

• 18√9

Simplify 4√75

• 4√5
• 12√5
• 20√3
• 7√3

√48

• 4√2
• 6√3
• 4√3
• 4√2

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

• b = 9, b = -9
• b = 3, b = -3
• b = 8, b = -8
• no solutionb

Solve for x: 
(x+6)²=49

• x=7,12
• x=±7
• x=1,-13
• x=43,-55