Question

Sistem persamaan linier
x+2y=-3
y+2z=4
x+y+2z=5
mempunyai himpunan
penyelesaian (x,y z) nilai dari 3(x+z) adalah....

Answer 1

Substitusi pers. 3 dan 2
x + y + 2z = 5
y + 2z = 4 -
x = 1
Substitusi x =1 ke pers. 1
x + 2y = -3
1 + 2y = -3
2y = -3-1
2y = -4 ---> y= -2
substitusi y= -2 ke pers. 2
y + 2z = 4
-2 + 2z = 4
2z= 6 ---> z= 3
Jadi, nilai 3(x+z)= 3(4) = 12

Answer 2

X+2y=-3 ......... 1
y+2z=4 .......... 2
x+y+2z=5 ........ 3
2 & 3
y+2z=4 
x+y+2z=5
_________ -
x = -1
x + 2y = -3
-1 + 2y = -3
2y = -2
y = -1