Question

Tolong dengan metode substitusi saja. untuk besokkk

Answer 1

X-y+z=7
x+2y+3z= 5
2x-y-z=-5

x= 7+y-z
7+y-z+2y+3z=5
y+2y-z+3z=5-7
3y+2z= -2

2x-y-z=-5
2(7+y-z)-y-z=-5
14+2y-2z-y-z=-5
2y-y-2z-z=-5-14
y-3z=-19
y=-19+3z
3(-19+3z)+2z=-2
-57+9z+2z=-2
11z=-2+57
11z=55
z=55/11
z=5
y=-19+3z
y= -19+3(5)
y= -19+15
y=-4
x=7+y-z
x=7+(-4)-5
x=7-4-5
x=-2
maka x= -2, y = -4 dan z= 5