Answer: {y,x}={2,8}
// Solve equation [2] for the variable y
[2] y = -2x + 18
// Plug this in for variable y in equation [1]
[1] (-2x+18) - x = -6
[1] - 3x = -24
// Solve equation [1] for the variable x
[1] 3x = 24
[1] x = 8
// By now we know this much :
y = -2x+18
x = 8
// Use the x value to solve for y
y = -2(8)+18 = 2
Solution :
{y,x} = {2,8}
