Review of Proportional Relationships in Equations

• Set the sum of 7 and 8 equal to the sum of 24 and x, and then solve fro x. 

• Set the sum of 7 and 24 equal to the sum of 8 and x, and then solve for x.

• Set the product of 7 and 8 equal to the product of 24 and x, and then solve for x.

• Set the product of 7 and 24 equal to the product of 8 and x, and then solve for x.

• because the cross sums of the proportion are equal

• because the cross differences of the proportion are equal

• because the cross products of the proportion are equal

• because the cross quotients of the proportion are equal

• because 192 divided by 32 is equal to 6

• because 192 divided by 36 is equal to 6

• because if you substitute 6 into the equation for x and cross multiply, you get 1,152= 1,152

• because if you substitute 6 into the equation for x and cross multiply, you get 1296 = 1296

The cost of toothpaste is $6.00 for 3 tubes. At this rate, how much do 12 tubes of toothpaste cost?

• $15

• $24

• $36

• $72

Sarah drove 40 miles per hour. In 3 hours, Sarah drove 120 miles. Which is a valid proportion to represent this description?

On Monday, the Dairy Barn sold 14 waffle cones for every 6 sugar cones. On Tuesday, the Dairy Barn sold 7 waffle cones for every 3 sugar cones. Which proportion can be used to represent the cone sales?

• 2

• 10

• 40

• 72

A group of 32 players forms 4 volleyball teams. If there are 96 players, how many teams can be formed?

• 3 teams

• 8 teams

• 12 teams

• 24 teams

Which equation represents a proportional relationship that has a constant of proportionality equal to –10?

• y = x-10

• y= x/-10

• y= -10x

• y=10