Steply

Simplify 27^(1/3)

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

Step by step

The question

Question: work out 27^(1/3).

27^(1/3)

A fraction power has two jobs.

The bottom number, 3, says which root: the cube root.

The top number, 1, says which power.

a^(m/n) = (n√a)m

Careful!

The power is not times.

27 times 1/3 is a different number.

Careful: not 27^(1/3) = 27 × 13 ✗

1 Write it as a root

The bottom is 3, so it is the cube root of 27.

The top is 1: power 1 changes nothing.

= 3√27

∛27 is 3, because 3 × 3 × 3 is 27.

3 × 3 × 3 = 27

So 27^(1/3) = 3.

= 3

2 Check

Let's check: 3 times itself 3 times.

We get 27.

So the answer is right!

3 × 3 × 3 = 27

Let's look back.

First: write it as a root.

Last: check.

Answer
= 3

Your turn

Try this one yourself, then check:

Work out 16^(1/4)
Show the answer
2

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