The variable y is directly proportional to the variable x. If y = 21 when x = 9, what is the value of y when x = 12?.

28

Step-by-step explanation:

So we can represent the x-y relationship with a fraction, 21/9(y/x)

Let’s take the unknown y number as “y”

So y/12=21/9(since they are proportional they equal each other)

1)cross multiply:

9y=12*21

9y=252

Divide both sides by 9

Y=28

Hope this helps!