Solving Proportions

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you determine if two ratios form a proportion?

Back

Two ratios form a proportion if the cross products are equal.

Front

What is the cross product of the ratios a/b and c/d?

Back

The cross product is ad and bc. If ad = bc, then a/b = c/d.

Front

Solve the proportion: 2/3 = x/9

Back

x = 6.

Front

What is the first step in solving a proportion?

Back

The first step is to cross-multiply the ratios.

Front

If 4/5 = x/20, what is x?

Back

x = 16.

Front

What does it mean if two ratios do not form a proportion?

Back

It means that the cross products are not equal.

Front

Solve the proportion: 3/4 = 6/x

Back

x = 8.

Front

What is the relationship between equivalent ratios?

Back

Equivalent ratios have the same value when simplified.

Front

If a/b = c/d, what can you say about a, b, c, and d?

Back

a and d are the extremes, and b and c are the means.