Concepts 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 it mean to cross-multiply?

Back

Cross-multiplying 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 ad = bc.

Front

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

Back

The first step is to cross-multiply: 3 * 12 = 4 * x.

Front

What is the solution to the proportion 3/4 = x/12?

Back

x = 9.

Front

How do you round a number?

Back

To round a number, look at the digit to the right of the place value you are rounding to. If it's 5 or more, round up; if it's less than 5, round down.

Front

What is the solution to the proportion 5/x = 10/20?

Back

x = 10.

Front

What is the value of x in the proportion 2/3 = x/9?

Back

x = 6.

Front

If 4/x = 8/16, what is x?

Back

x = 2.