Steply

Simplify (1 + 2/x)/(1/x)

Step by step, with the reason for every step · Complex fractions · Algebra 2

Step by step

The question

Question: simplify this fraction.

On top: 1 + 2 over x.

At the bottom: 1 over x.

A fraction with fractions inside is called a complex fraction.

1 + 2x1x

1 Find the common bottom

The small fraction has the bottom x.

The smallest thing they all go into is x.

small bottoms: x
common bottom: x

Careful!

We multiply EVERY part by x, also the part with no small bottom.

Leaving it out is the usual mistake.

Careful: every part times x, the whole numbers too

2 Times x on top and bottom

x/x is 1.

Times 1 does not change the value.

xx = 1

We multiply the top and the bottom by x.

Then the small fractions go away.

= x × (1 + 2x)x × (1x)

3 Multiply every part

Every part times x.

x times 1 is x.

x times 2/x: the bottom x goes into x, so we get 2.

x × 1 = x
x × 2x = 2
x × 1x = 1

So we get x + 2.

The bottom is just 1, so we leave it out.

No more small fractions!

So the answer is x + 2.

= x + 2

One more thing: no bottom can be 0.

So x can't be 0.

x ≠ 0

4 Check

Let's check with a number: x = 2.

In the question, the long way: the top is 2, the bottom is 1/2.

x = 2: top 1 + 1 = 2, bottom 12 = 12

Top divided by bottom: 4.

question: 2 ÷ 12 = 4

Our answer with x = 2 gives 4 too.

It works!

answer: 2 + 2 = 4

Let's look back.

First: find the common bottom.

Then: times x on top and bottom.

Then: multiply every part.

Last: check.

Answer
= x + 2

Your turn

Try this one yourself, then check:

simplify (1 + 3x) ÷ (1x)
Show the answer
x + 3

More from Complex fractions

The whole lesson: Complex fractions →