Diketahui sistem persamaan x – 2y = 10 dan 3x – y = 15, nilai 5x – 4y adalah

Jawaban:

~ Math

x – 2y = 10 |×3

3x – y = 15 |×1

3x – 6y = 30

3x – y = 15

___________ _

-5y = 15

y = -3

x – 2y = 10

x – 2(-3) = 10

x + 6 = 10

x = 4

5x – 4y

5(4) – 4(-3)

20 + 12

32 [B]

3 – Des – 2020