selesaikan sistem persamaan linear berikut dengan matriks a. 2x-3y=1 dan x+2y=11 b. 3x+y=7 dan x-3y=11 tolong dibantu ya,

Mapel : Matematika
Kelas : VIII SMP
Materi : SPLDV

Pembahasan :
2x - 3y = 1
x + 2y = 11 —» 2x + 4y = 22

Eliminasi...
2x + 4y = 22
2x - 3y = 1
——————— (-)
7y = 21
y = 3

Substitusi...
x + 2y = 11
x + 2(3) = 11
x = 11 - 6
x = 5

Hp : {5 , 3}

————————————————
3x + y = 7 —» 9x + 3y = 21
x - 3y = 11

Eliminasi...
9x + 3y = 21
x - 3y = 11
——————— (+)
10x = 32
x = 32/10
x = 16/5

Substitusi...
x - 3y = 11
16/5 - 3y = 11
3y = 16/5 - 11
3y = 16/5 - 55/5
3y = -39/5
y = -13/5

Hp : {16/5 , -13/5}