Diketahui sistem persamaan linier 8x + 7y = 3 dan -4x + 3y = 31. Nilai -5x + 4y adalah ….

Jawaban:

8x + 7y = 3. (×1)

-4x + 3y = 31 (×2)

—————————-

8x + 7y = 3

-8x + 6y = 62. +

———————–

13y = 65

y = 5

8x + 7y = 3

8x + 7(5) = 3

8x + 35 = 3

8x = -32

x = -4

-5x + 4y = -5(-4) + 4(5) = 20 + 20 = 40

maap kalo salah^^