Let me explain.
First we have to add our 8 to our -3.Anything that crosses the = sign changes signs:
5x + 8 = 3x -3-8
Which gives us:
5x= 3x -11
Now, we carry over 3x which gives us:
2x=-11
The last step is to divide.
2x/2=-11/2
Since we don't have any common terms, the fraction stays as it is.
=-11/2