Substitution method is used to solve the linear system of equations for one or more variables.
Consider the first equation y = 3x + 3 -----(1)
In equation (1) plug in y=x-1, we get
x -1 = 3x + 3
Add -3x on both side , we get
x-3x -1 = 3x-3x +3
-2x-1=0 + 3
Now add +1 on both sides, we get
-2x-1+1= 3+1
-2x + 0 =4
Now divide both side by -2
-2x/-2= 4/-2
X= -2
Now put x=-2 in the the second equation,
y=x-1
y=(-2)-1
y=-3
Solution(-2,-3)
