Question

Diketahui sistem persamaan linear berikut:
2x+3y-z=5
x+y+z=9
x-2y-z=-7

Answer 1

X+y+z+=9
x=9-y-z

2x+3y-z=5
2(9-y-z)+3y-z =5
18-2y-2z+3y-z=5
y-3z=-13
y=-13+3z

x-2y-z = -7
(9-y-z) - 2y-z = -7
(9-(-13+3z)-z) - 2(-13+3z) - z = -7
-11z = -55
z=5

y = -13+3z = -13+3(5) = 2
x = (9 -y-z) = (9-2-5) = 2

jadi x= 2, y = 2, z=5