Question 1163638
your equations are:


3x + 3y = 3
-3x - 2z = -11
y + z = -1


solve for z in the third equation to get z = -y - 1


replace z in the second equation to get -3x - 2 * (-y-1) = -11.
simplify to get -3x + 2y + 2 = -11
subtract 2 from both sides of the equation to get -3x + 2y = -13


you can now solve the first 2 equations simultaneously.
they are:


3x + 3y = 3
-3x + 2y = -13


add the equations together to get:
5y = -10
solve for y to get y = -2


replace y with -2 in the first equation to get:
3x + 3y = 3 becomes 3x - 6 = 3
add 6 to both sides of that equation to get 3x = 9
solve for x to get x = 3


you now have x = 3 and y = -2


go back to the third equation and replace y with -2
y + z = -1 becomes -2 + z = -1
add 2 to both sides of that equation to get z = 1


you now have x = 3 and y = -2 and z = 1


go back to youor 3 original equations and replace x and y and z with their respective values to see if those equations are true.


3x + 3y = 3 becomes 3*3 - 3*2 = 3 which becomes 9 - 6 = 3 which becomes 3 = 3 which is true.


-3x - 2z = -11 becomes -3*3 - 2*1 = -11 which becomes -9 - 2 = -11 which becomes - 11 = -11 which is true.


y + z = -1 bcomes -2 + 1 = -1 which becomes -1 = -1 which is true.


it looks like x = 3, y = -2, z = 1 is your solution.


it can be shown in (x,y,z) format as (3,-2,1)