Tentukan himpunan penyelesaian dari sistem persamaan berikut dengan metode substitusi jika x, y variabel pada himpunan bilangan real (a.) 2x + y + 5 = 2 dan 3y

Bab SPLDV
Matematika SMP Kelas VIII

a] 2x + y + 5 = 2
y = -2x + 2 - 5
y = -2x - 3

3y + 2x = -5
3(-2x - 3) + 2x = -5
-6x - 9 + 2x = -5
-4x = -5 + 9
x = 4 : (-4)
x = -1

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

HP = { (-1, -1) }

b] 2x - y = 3
y = 2x - 3

4x + 3y = 6
4x + 3(2x - 3) = 6
4x + 6x - 9 = 6
10x = 6 + 9
x = 15/10
x = 3/2

y = 2x - 3
y = 2 . (3/2) - 3
y = 3 - 3
y = 0

HP = { (3/2, 0) }

c] 2x + 4y = 6
2x = -4y + 6
x = -2y + 3

4x + 8y - 8 = 0
4 (-2y + 3) + 8y - 8 = 0
-8y + 12 + 8y - 8 = 0
0y + 4 = 0 (tidak dapat diselesaikan)

HP = { }