Question

2x - y = 7
x - y = 1
tentukan nilai 2x - 3y =
berserta caranya

Answer 1

Eleminasi (y)
2x-y = 7
x-y = 1
------- (-)
x-0y = 6
y = 6/x
y = 6

Substitusi (y=6)
x-y = 1
x-6 = 1
x= 1+6
x= 7

2x-3y
2(7)-3(6)
14-14 = 0

Jadi, nilai 2x-3y adalah 0.

Answer 2

2x-y = 7 ---> 2x-7 = y .... (pers 1)
x-(2x-7)=1
x - 2x +7 = 1
-x = 1-7
-x = -6
x = 6

substitusikan x ke pers 1
2x-7= y
2(6) - 7 = y
12-7 = y
5 = y
jadi 2x -3y = 2(6) - 3(5) = 12 - 15 = -3