How do you simplify root [ 5] { 243x ^ { 25} y ^ { 15} }?

1 Answer
Dec 14, 2016

3x^5y^3

Explanation:

root(5)(243x^25y^15)

To evaluate a fifth root, convert each part of the radicand (the part of the problem under the radical symbol) to a power of five.

In this example, 243=3^5.

And using the exponent rule (x^a)^b=x^(ab),
x^25=(x^5)^5 and y^15=(y^3)^5

root(5)(3^5 (x^5)^5(y^3)^5)

The fifth root of a base raised to the fifth power is the base, i.e.
root(5)(a^5)=a.

root(5)(3^5 (x^5)^5(y^3)^5)=3x^5y^3