Ok, so:
We're going to solve the next equation:
5x + 4 = 3x - 18
For this, we have to put "x" terms and numbers in different sides, like this:
5x - 3x = -4 - 18
Remember that, when any number of term passes to the other side, it does with different sign.
Now, we got:
2x = -22
And finally, 2 divides the other side:
So, x = -11