Steply

Simplify 25^(1/2)

Step by step, with the reason for every step · Rational exponents · Algebra 1

Step by step

The question

Question: work out 25^(1/2).

25^(1/2)

A fraction power has two jobs.

The bottom number, 2, says which root: the square root.

The top number, 1, says which power.

For the square root, the small 2 is not written.

a^(m/n) = (n√a)m

Careful!

The power is not times.

25 times 1/2 is a different number.

Careful: not 25^(1/2) = 25 × 12 ✗

1 Write it as a root

The bottom is 2, so it is the square root of 25.

The top is 1: power 1 changes nothing.

= √25

√25 is 5, because 5 × 5 is 25.

5 × 5 = 25

So 25^(1/2) = 5.

= 5

2 Check

Let's check: 5 times itself 2 times.

We get 25.

So the answer is right!

5 × 5 = 25

Let's look back.

First: write it as a root.

Last: check.

Answer
= 5

Your turn

Try this one yourself, then check:

Work out 81^(1/4)
Show the answer
3

More from Rational exponents

The whole lesson: Rational exponents →