#1**+1 **

Best Answer

0.25 is 1/4, so 81^0.25 is 81^(1/4) This means the fourth root of 81. That is, it is a number which, when raised to the power of 4 equals 81.

3^4 = 3*3*3*3 → 9*9 → 81

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Alan
Jul 2, 2017

#2**0 **

Are you not happy with Alan's answer? Why?

You take the square root of 81 =sqrt(81) = 9. Now, you take the square of 9 this time=sqrt(9) = 3.

In other words, when you see 81^0.25 =81^1/4, it means that you must take the square root of 81 twice, or the square root of a square root =81^1/2 =9^1/2 =3 because 3^2 x 3^2 =81.

Guest Jul 2, 2017