Question

What is the value of x in the equation 4 x plus 8 y equals 40, when y equals 0.8?

Answer 1

`4x + 8y = 40 \\ 4x + 6.4 = 40 \\ 4x = 40 - 6.4 \\ 4x = 33.6 \\ x = 8.4`

Answer 2

now first of all we should plug in 0.8 to y .

now we have this simple equation: 4x+8.(0.8)=40

4x+6.4=40

4x=33.6

x=8.4 (hope it helps :) )

Explanation: