jika persamaan x+y+2=3,x-y+z=1,2x+y-3z=10tentukan nilai 3x+2y+5z

x+y+z = 3
x-y+z = 1 (-)
2y = 2
y = 1

x+ y+z = 3
x+1+z = 3
x+z = 2 .........(1)

2x+y-3z =10
x+y+z = 3 (-)
x - 4z = 7 ...... (2)

x-4z = 7
x+z = 2 (-)
-5z= 5
z= -1

x+z = 2
x-1 = 2
x = 3

jadi,
=3x +2y + 5z
=3(3) + 2(1) + 5(-1)
=9+2-5
= 6