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 isolate the 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 = 6/12?

Back

Cross-multiply to get 3*12 = 6*x.

Front

What is the solution to the proportion 4/x = 8/16?

Back

x = 2.

Front

What is the value of k in the proportion k/5 = 15/25?

Back

k = 3.

Front

If 2/3 = x/9, how do you find x?

Back

Cross-multiply to get 2*9 = 3*x, so x = 6.

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.