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 two ratios and then solve for the unknown variable.

Front

What is the cross-multiplication method?

Back

The cross-multiplication method involves multiplying the numerator of one ratio by the denominator of the other ratio and setting the two products equal to each other.

Front

If a car drives 110 miles using 5 gallons of gas, what is the unit rate of miles per gallon?

Back

The unit rate is 22 miles per gallon (110 miles ÷ 5 gallons).

Front

How can you set up a proportion to find out how far a car can drive with a different amount of gas?

Back

Set up the proportion using the known distance and gas amount, and the unknown distance and gas amount.

Front

What is the formula for finding the distance driven based on gas used?

Back

Distance = (Miles per gallon) x (Gallons of gas used).

Front

If a proportion is set up as a/b = c/d, what does it mean?

Back

It means that the ratio of a to b is equal to the ratio of c to d.

Front

What is the first step in solving a proportion problem?

Back

Identify the known values and the unknown variable.

Front

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

Back

Substitute the solution back into the original proportion to see if both sides are equal.

Front

What is an example of a real-world application of proportions?

Back

Determining the cost of items based on unit prices, such as finding the price per item when buying in bulk.