Question

X+y=1
y+z=6
2x+y+z=4
x+z=??

Answer 1

( 2x + y + z ) - ( x + y ) = 4 - 1
2x + y + z - x - y = 3
2x - x + y - y + z = 3
x + z =3

Answer 2

X + y = 1 jadi x = 1 - y
Y + z = 6 jadi z = 6 - y
Masukkan ke persamaan 2x + y + z = 4
2(1-y) + y + (6-y) = 4
2 - 2y + y + 6 - y = 4
8 - 2y = 4
-2y = 4-8 = -4
Y = -4/-2 = 2

Masukkan y ke persamaan x + y = 1
X + 2 = 1
X = 1-2 = -1

Masukkan y ke persamaan y + z = 6
2 + z = 6
Z = 6-2 = 4

Jadi x + z =
-1 + 4 = 3

Semoga membantu