x - y = 3x + 3y = 9
Solve for one of the variables in the first equation (in this case, I will solve for X):X = Y + 3Then use that value of X in the second equation to solve for Y:X + 3Y = 9(Y + 3) + 3Y = 94Y + 3 = 94Y = 6Y = 1.5Use the value of Y we just found in the X equation we created:X = Y + 3X = 1.5 + 3X = 4.5Therefore X = 4.5 or 9/2 and Y = 1.5 or 3/2.
X - y = 3 is the same as x=3+y 3+y+3y = 9 3+4y=9 4y=9-3 4y=6 y=6/4 y=3/2 x-(3/2)=3 x=3+(3/2) x=6/2+3/2 x=9/2