16Hit1600
Advanced MathEasyPositive fourth root

Advanced Math practice question

If x⁴ = 81 and x > 0, what is the value of x?

Answer: 3

3 × 3 × 3 × 3 = 81.

Common wrong answers

If you answered 9
9 is the square root of 81, not the fourth root.
If you answered 20.25
20.25 divides 81 by 4.
If you answered -3
−3 is ruled out because x > 0.

More Advanced Math questions

Not affiliated with the College Board. SAT is a trademark of the College Board.