Answer:
{x,y} = {5,6}
Explanation:
// Solve equation [1] for the variable x
[1] x = y - 1
// Plug this in for variable x in equation [2]
[2] 2•(y -1) - y = 4
[2] y = 6
// Solve equation [2] for the variable y
[2] y = 6
// By now we know this much :
x = y-1
y = 6
// Use the y value to solve for x
x = (6)-1 = 5