Respuesta :

Answer:

When x = 8.4 and y = .8 then 4x + 8y = 40

Step-by-step explanation:

4x + 8y = 40

y = .8

Let's solve for x by substituting .8 for y (since y is given)

4x + 8(.8) = 40

4x + 6.4 = 40   Subtract 6.4 from both sides.

4x + 6.4 - 6.4 = 40 - 6.4

4x = 33.6  Divide each side by 4

4x/4 = 33.6/4   4 cancels on the left because 4/4 = 1

x = 33.6/4

x = 8.4

So when x = 8.4 and y = .8 then 4x + 8y = 40