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

If 36 baseball cards cost $18, what is the cost of 1 baseball card?

Back

The cost of 1 baseball card is $0.50.

Front

If Troy has $9, how many baseball cards can he buy if each costs $0.50?

Back

Troy can buy 18 baseball cards.

Front

What does it mean to cross-multiply in a proportion?

Back

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

Front

Solve for x: 4/x = 2/8

Back

x = 16.

Front

What is the first step in solving the proportion 3/4 = x/12?

Back

Cross-multiply to get 3 * 12 = 4 * x.

Front

If 5/10 = x/20, what is the value of x?

Back

x = 10.

Front

What is the relationship between equivalent ratios?

Back

Equivalent ratios represent the same relationship between quantities.

Front

How can you check if two ratios are equivalent?

Back

You can check by cross-multiplying and seeing if the products are equal.