Question

Pasangan (x,y,z) yang merupakan penyelesaian sistem persamaan.
3x+y+z=7
2x+y-z=3
x+y+z=3
a.(2,0,1)
b.(0,2,1)
c.(2,2,1)
d.(1,2,0)
e.(2,1,0)

Answer 1

3x+y+z=7 ==>z=7-3x-y
2x+y-z=3
x+y+z=3
Jwb:
2x+y-z=3
2x+y-(7-3x-y)=3
2x+y-7+3x+y=3
5x+2y =3+7
5x+2y =10

x+y+z=3
x+y+(7-3x-y)=3
x+y+7-3x-y =3
-2x =3-7
-2x =-4
x = -4/-2
x =2
5x+2y=10
5(2)+2y=10
10+2y =10
2y= 10-10
y=0
z=7-3x-y
= 7-3(2)-0
=7-6
=1
Jadi x=2 ,y=0 ,z=1
Jawabannya a.(2,0,1)