In this video, we will be learning how to solve proportions using cross-multiplication. After you finish this lesson, view all of our Pre-Algebra lessons and practice problems.

For Example:

First we cross-multiply

Then we divide by 5 to isolate *x*

## Examples of Solving Proportions

### Example 1

First, we have to cross-multiply.

then

Next, distribute to

Subtract from both sides

Divide from both sides to get

Our final answer is

### Example 2

First, we have to cross-multiply.

then

Next, distribute to

Add from both sides

Divide from both sides to get

Our final answer is

## Video-Lesson Transcript

In this video, we will be learning how to solve proportions using cross-multiplication.

Ratio = Ratio

Or

Solving Proportions comes in when there is an unknown.

Let’s say we have

We have to cross-multiply.

then

We have

Then we get the value of

But what about it is not a perfect multiplier?

For example,

In this case, we cross-multiply then

So we have

Here we have to

So

Here’s another example.

Let’s cross-multiply, then

We have to distribute

And we’ll have

To get the value of we have to

Our final answer is