SAT Math Question of the Day

Math Category: Roots Level 2:

Q: √ 45

  1. 5 √ 2
  2. 5 √ 3
  3. 2 √ 5
  4. 3 √ 5
  5. 4 √ 5

UNANSWERED.

The correct answer is D.

A: The answer is 3 √ 5 .
√ 45 = √ (3)(3)(5)
There are two 3's under the root sign, so the 3 can be moved to outside the root, leaving 3 √ 5 .