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 cross-multiplication involve?

Back

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

Front

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

Back

The result is a*d = b*c.

Front

What is the first step in solving the proportion 3/x = 12/16?

Back

Cross-multiply to get 3 * 16 = 12 * x.

Front

What is the solution to the proportion 3/x = 12/16?

Back

x = 4.

Front

If 5/10 = x/20, how do you find x?

Back

Cross-multiply to get 5 * 20 = 10 * x, then solve for x.

Front

What is the value of x in the proportion 5/10 = x/20?

Back

x = 10.

Front

What is a key property of proportions?

Back

If two ratios are equal, then their cross-products are also equal.

Front

How can proportions be used in real life?

Back

Proportions can be used to solve problems involving scaling, such as recipes or maps.