Tentukan selesaian dari sistem persamaan berikut a. x + 3y = 5 x-y=-3 b. 4x+3y=-5 -x+3y=-10 c. 2x+5y=16 3x-5y=-1 d. 3x-2y=4 6x-2y=-2

a) eliminasi x
x + 3y = 5
x - y = -3
_______-
4y = 8
y = 8 : 4
y = 2
substitusi y = 2 ke persamaan x - y = -3
x - (2) = -3
x = -3 + 2
x = -1
HP (-1, 2)

b) eliminasi 3y
4x + 3y = -5
-x + 3y = -10
___________-
5x = 5
x = 5 : 5
x = 1
substitusi x = 1 ke persamaan -x + 3y = -10
-(1) + 3y = -10
3y. = -10 + 1
3y = -9
y = -9 : 3
y = -3

HP(1, -3)


c) eliminasi 5y
2x + 5y = 16
3x - 5y = -1
__________+
5x = 15
x = 15 : 5
x = 3
substitusi x = 3 ke persamaan 3x - 5y = -1
3(3) - 5y = -1
5y = 9 + 1
5y = 10
y = 10 : 5
y = 2

HP (3, 2)

d) eliminasi 2y
3x - 2y = 4
6x - 2y = -2
_________-
-3x = 6
x = 6 : -3
x = -2
substitusi x = -2 ke persamaan 6x - 2y = -2
6(-2) - 2y = -2
2y = -12 + 2
2y = -10
y = -10 : 2
y = -5

HP (-2, -5)