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 unknown variable.

Front

What does it mean for two ratios to form a proportion?

Back

Two ratios form a proportion if their cross products are equal.

Front

If a/b = c/d, what is the cross-multiplication?

Back

The cross-multiplication is a*d = b*c.

Front

Solve the proportion: 3/4 = x/12

Back

x = 9.

Front

Solve the proportion: 5/x = 15/12

Back

x = 4.

Front

What is the first step in solving a proportion?

Back

The first step is to set the two ratios equal to each other.

Front

If 2/3 = x/9, what is x?

Back

x = 6.

Front

What is the relationship between equivalent ratios?

Back

Equivalent ratios are ratios that express the same relationship between numbers.

Front

Solve the proportion: 8/10 = x/25

Back

x = 20.