7x+3y=15 dan 4x-5y=22

7x+3y = 15 | x5
4x-5y = 22 | x3
.
35x+15y= 75
12x-15y = 66
___________+
47x = 141
x = 141/47
x = 3
.
.
7x+3y = 15
7.3+3y = 15
21+3y = 15
3y = 15-21
3y = -6
y = -6/3
y= -2

7x+3y=15...(x4)
4x-5y=22....(x7)
--------------------
28x+12y=60
28x-35y=154
------------------ --
        47y=-94
            y=-2
substitusi nilai y=-2 ke persamaan 7x+3y=15
 7x+3(-2)=15
  7x=21
    x=3
jadi  x=3 dan y=-2