4.1 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

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

Back

The cross-multiplication method states that a * d = b * c.

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

Solve the proportion: 5/10 = x/20.

Back

x = 10.

Front

What does it mean if two ratios are equivalent?

Back

It means that they represent the same relationship between quantities.

Front

How can you check if your solution to a proportion is correct?

Back

You can check by substituting the solution back into the original proportion to see if both sides are equal.

Front

Solve the proportion: 8/x = 4/2.

Back

x = 4.

Front

What is the relationship between the means and extremes in a proportion?

Back

In a proportion a/b = c/d, a and d are the extremes, and b and c are the means.

Front

If 2/3 = x/9, what is x?

Back

x = 6.