jika (x,y,z) merupakan solusi spltv x+y=1, y+z=3, z+x=6 maka nilai xyz adalah..... tolong bantu beserta jalannya,,,!

eliminasi
x+y = 1
z+y = 3
------------ -
x-z = -2

eliminasi
x-z = -2
x+z = 6
------------ -
-2z = -8
z= 4

substitusi
x+z = 6
x+4 = 6
x = 6-4 = 2

substitusi
x+y = 1
2+y = 1
y= 1-2 = -1

jadi nilai
x= 2
y= -1
x = 4