(1) Get rid of the fraction by multiply both sides by (4-x), we now have y(4-x)=3x+5. (2) Expand any brackets, so 4y-py=3x+5. (3) Rearrange to get all the x to one side: 4y-5=3x+px. (4) Factorise x because we want x by it self in the end: leaving us 4y-5=x(3+y). (5) Divide both side by 3+y, hence x=(4y-5)/(3+y).