a.) 2x – 3y = 3 dan y = 2x – 1 b.) 5x - y = 3 dan 10x - 5y = 15 c.) x + 4y = 8 dan 2x - y = 3 ini bukan pilihan ganda

1.]
2x - 3y = 3
2x - y = 1
–––––––– (–)
-2y = 2
y = -1

Subtitusi ke pers. 2x - 3y = 3
2x - 3(-1) = 3
2x = 0
x = 0

HP : {(0 , -1)}

2.]
5x - y = 3 |x 2|
⬇ ⬇ ⬇ ⬇ ⬇
10x - 2y = 6
10x - 5y = 15
–––––––––– (–)
3y = -9
y = -3

5x - (-3) = 3
5x = 0
x = 0

HP : {(0 , -3)}

3.]
x + 4y = 8 |x 2|
⬇ ⬇ ⬇ ⬇ ⬇
2x + 8y = 16
2x - y = 3
––––––– (–)
9y = 13
y = 13/9

2x - 13/9 = 3
2x = 3 + 13/9
x = 20/9

HP : {(20/9 , 13/9)}

Cara yg beda.. (mungkin)

A][
y = 2x - 1
substitusi
2x - 3y = 3
2x - 3(2x - 1) = 3
-4x = 3 - 3
x = 0
y = 2x - 1 = -1

HP = {(0,-1)}

B][
5x - y = 3
y = 5x - 3
substitusi
10x - 5y = 15
2x - y = 3
2x - (5x - 3) = 3
-3x = 3 - 3
x = 0
y = 5x - 3 = -3

HP = {(0,-3)

C][
x + 4y = 8
x = 8 - 4y
substitusi
2x - y = 3
2(8 - 4y) - y = 3
-9y = 3 - 16
y = 13/9
x = 8 - 4y = 8 - 52/9 = 20/9

HP = {(20/9 , 13/9)}