Let's simplify and solve the first two equations.
If we subtract 2 from both sides to x+y+2=6, it becomes x+y=4.
If we subtract 2 from both sides to 2x-y+2=3, it becomes 2x-y=1.
Now, If we add the two equations, x+2x=3x, y+(-y)=0,4+1=5. ->3x=5. Thus, x=3/5=0.6.
Because x+y=4, y=4-0.6=3.4.
Now plug in the values of x and y in the 3rd equation, and we get 3(0.6)+0(3.4)-z=1.8-z=0. So, x=1.8-0=1.8.
Review: x=0.6, y=3.4, z=1.8.
