If and , what is the value of ?

Answer and explanation

Correct answer: C.

  1. Step 1: Isolate the radical term on the left side: .
  2. Step 2: Square both sides of the equation: . Subtract from both sides: .
  3. Step 3: Square both sides to solve for : . Check: .
Answer
.

Practise more Powers and roots.

Free questions with an explanation for every one, and full timed GMAT mock tests.

If x >= 0 and sqrt(x + 7) - sqrt(x)… | GMAT Powers and roots