Use the strategy you developed i
a. a/7 + a/3 = 10

A=21

Step-by-step explanation:

a/7 + a/3 = 10

3a/21+7a/21=210/21

3a+7a=210

10a=210

a=21

step-by-step explanation:

in problems involving proportions, we can use cross products to test whether two ratios are equal and form a proportion. to find the cross products of a proportion, we multiply the outer terms, called the extremes, and the middle terms, called the means.

hope it