I am new to this area of maths and would like to know from the following equation:

dx/dt -2x = 4 with conditions of t = 0 and x = 1

when rewritten to give sx - 1 - 2x = 4/s how do you rearrange to give an expression for x?

I have the answer as s + 4/s(s-2) but dont know how it has come to this.

Thanks in advance :)