Jawaban:

metode yang dipakai yaitu eliminasi dan substitusi

1. a. metode eliminasi

5x - y = 7 | ×2 | 10x - 2y = 14

10x - 6y = -18 | ×1 | 10x - 6y = -18 _

4y = 32

y = 32/4 = 8

b. metode substitusi

y = 8

5x - y = 17

5x - (8) = 17

5x = 17 + 8

5x = 25

x = 25/5 = 5

maka nilai x = 5, nilai y = 8

2. a. metode eliminasi

5x + 6y = 48 | ×1 | 5x + 6y = 48

7x + 3y = 60 | ×2 | 14x + 6y = 120 _

-9x = -72

x = -72/-9 = 8

b. metode substitusi

x = 8

5x + 6y = 48

5 (8) + 6y = 48

40 + 6y = 48

6y = 48 - 40

y = 8/6

y = 1,3

maka nilai x = 8, nilai y = 1,3