Answer:
{y,x} = {0,4}
Explanation:
// Solve equation [2] for the variable y
[2] y = 2x - 8
// Plug this in for variable y in equation [1]
[1] (2x-8) + x = 4
[1] 3x = 12
// Solve equation [1] for the variable x
[1] 3x = 12
[1] x = 4
// By now we know this much :
y = 2x-8
x = 4
// Use the x value to solve for y
y = 2(4)-8 = 0