SOLUTION:

Question 28204:
Answer by allie8(1) (Show Source): You can put this solution on YOUR website!
square root of 72 = 8.48528... per calculator, to solve manually: 9 * 8 = 72 = 9 is a perfect square so the equation becomes 3 sq rt 8 but then 8 breaks down to 4 * 2 and 4 is a perfect square so take 3 * 2 = 6 sq rt 2