tentukan nilai u,x,y dan z dari X+2y=5 Y+2z=8 Z+2u=11 Y+2x=6

x + 2y = 5
x = 5 - 2y

y + 2x = 6
y + 2(5 - 2y) = 6
y + 10 - 4y = 6
-3y = 6-10
-3y = -4
y = 4/3

x = 5 - 2y
x = 5 - 2(4/3)
x = 5 - 8/3
x = 7/3

y + 2z = 8
4/3 + 2z = 8
2z = 8 - 4/3
2z = 20/3
z = 20/6
z = 10/3

z + 2u = 11
10/3 + 2u = 11
2u = 11 - 10/3
2u = 23/3
u = 23/6

maka
u = 23/6 = 3 5/6
x = 7/3 = 2 1/3
y = 4/3 = 1 1/3
z = 10/3 = 3 1/3