Y and x have a proportional relationship, and y = 12 when x = 8.

What is the value of x when y = 18?

show your work

Answer: x is 12

Step-by-step explanation:

For directly proportional relationship, both variables change in the same direction. It means that an increase in one variable will result to an increase in the other variable. A decrease in one variable will result to a decrease in the other variable.

y and x have a proportional relationship,

We will introduce a proportionality constant and replace the proportionality symbol with an equal to symbol. Thus

y = kx

When y is 12, x is 8

Substituting into the equation,

12 = k * 8

k = 12/8 = 1.5

The equation becomes

y = 1.5x

The value of x when y is 18 will be

18 = 1.5x

x = 18/1.5 = 12