Solve by substitution:
By considering the 3rd equation,
z=1+x
By considering the 2nd equation,
y=x+z=x+1+x=2x+1
Substitute these into the 1st equation,
x+(2x+1)+(1+x)=10
4x+2=10
2x+1=5
x=2
y = 2(2)+1 = 5
z = 1+(2) = 3
I love substitution method more, it's faster.