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 4/x = 8/16?

Back

Cross-multiply to get 4*16 = 8*x.

Front

Solve the proportion: 3/x = 9/12.

Back

x = 4.

Front

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

Back

x = 10.

Front

If 2/3 = x/12, how do you find x?

Back

Cross-multiply to get 2*12 = 3*x, so x = 8.

Front

What is a unit rate?

Back

A unit rate is a ratio that compares a quantity to one unit of another quantity.

Front

How do you find a unit rate from a proportion?

Back

Divide the numerator by the denominator to find the rate per one unit.