5x+2y=12 dan x-4y=-2 Tentukan nilai x dan y,tentukan harga 2x-3y

5x + 2y = 12 .... kali 2
10x + 4y = 24

10x + 4y = 24
x - 4y = -2
Jumlahkan
11x = 22
x = 2

x - 4y = -2
4y = 2 + 2
y = 1

⏺2x - 3y = 2.2 - 3.1 = 1

Mapel : Matematika
Kelas : VIII SMP
Materi : SPLDV

Pembahasan :
5x + 2y = 12
x - 4y = -2 |x 5| 5x - 20y = -10

Samakan...
5x = 5x
12 - 2y = -10 + 20y
20y + 2y = 12 + 10
22y = 22
y = 1

Substitusi...
x - 4y = -2
x - 4(1) = -2
x - 4 = -2
x = -2 + 4
x = 2

Maka...
2x - 3y = 2(2) - 3(1) = 4 - 3 = 1