y varies directly with x, and y = 5 when x = 4. What is the value of x when y = 8

Mathematics · Middle School · Sun Jan 24 2021

Answered on

Given the statement:

y varies directly with x, and y = 5 when x = 4.

Determine the value of x when y = 8

Solution:

In order to determine the value of x, when y = 8, we must first find for the constant of variation. This can be done by multiplying the value of x and y.

k = xy

k = (5)(4)

k = 20

20 = 8x

Divide both sides by 8 in order to determine the value of  x.

8x/8 = 20/8

x = 2.5

Final answer:

x = 2.5