Solving Proportions

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the terms and then solve for the variable.

Front

What does it mean to cross-multiply?

Back

Cross-multiplying means multiplying the numerator of one ratio by the denominator of the other ratio.

Front

If the ratio of boys to girls is 5 to 3, how can you express this as a fraction?

Back

The ratio can be expressed as 5/3.

Front

What is the first step in solving the proportion 5/3 = x/65?

Back

The first step is to cross-multiply: 5 * 65 = 3 * x.

Front

What is the value of x in the proportion 5/3 = x/65?

Back

x = 39.

Front

If you have the proportion 4/5 = x/20, how do you find x?

Back

Cross-multiply: 4 * 20 = 5 * x, then solve for x.

Front

What is the solution for x in the proportion 4/5 = x/20?

Back

x = 16.

Front

What does it mean if two ratios are equivalent?

Back

It means that they represent the same relationship between quantities.

Front

How can you check if your solution to a proportion is correct?

Back

You can check by substituting your solution back into the original proportion to see if both sides are equal.