Jika x dan y memenuhi sistem persamaan linear 2x-5y=15 dan 3x+4y=11, maka 2x+3y =… 8 poin
Jawab
2x-5y=15 [x 3]
3x+4y=11 [x 2]
————–
6x – 15y = 45
6x + 8y = 22
——————- –
-23 y = 23
y = -1
6x + 8y = 22
6x + 8(-1) = 22
6x – 8 = 22
6x = 30
x = 30/6
x = 15/3
Maka,
2x+3y
2(15/3) + 3(-1)
30/3 – 3
10 – 3
7