7x + 4y = 2
7x + 2y = 8
Subtract both equations
7x + 4y = 2
-
7x + 2y = 8
__________
2y = -6
Solve for y
y= - 6/2
y= -3
Replace y=-3 on any original equation and solve for x
7x + 4y= 2
7x + 4(-3)= 2
7x - 12 = 2
7x = 2 + 12
7x= 14
x = 14/7
x= 2
Solution = (2,-3)
