Himpunan penyelesaian dari 3x – 2y +7 =0 dan 2x +y -7 = 0 adalah

Diketahui :
– 3x – 2y + 7 = 0
– 2x + y – 7 = 0

Ditanya :
– Nilai x = ……?
– Nilai y = ……?

Penyelesaian :
– Nilai x :
3x – 2y + 7 = 0
3x – 2y = – 7

2x + y – 7 = 0
2x + y = 7

2x + y = 7
y = 7 – 2x

3x – 2y = – 7
3x – 2(7 – 2x) = – 7
3x – 14 + 4x = – 7
3x + 4x = – 7 + 14
7x = 7
x = 7/7
x = 1

– Nilai y :
y = 7 – 2x
y = 7 – 2
y = 5

Maaf Kalau Salah

3x – 2y + 7 = 0
3x – 2y = -7 ••• (1)
2x + y – 7 = 0
2x + y = 7 ••• (2)

3x – 2y = -7 | × 1 |
2x + y = 7 | ×2 |
———————–
3x – 2y = -7
4x + 2y = 14
—————— +
7x = 7
x = 1

2x + y = 7
2.1 + y = 7
2 + y = 7
y = 5