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