Given the system of the equations:
y = x + 4
x + y = 2
By substitution with y from the first equation at the second equation
so,
x + (x+4) = 2
solve to find x
so,
x + x + 4 = 2
2x = 2 - 4
2x = -2
Divide both sides by 2
x = -2/2 = -1
Substitute at the first equation with x to find y
So, y = -1 + 4 = 3
so, x = -1 and y = 3
so, the order pair which a solution is (-1 , 3)