you can start by simplifying the all the numbers by 3, because 3 is the common multiple. divide all of them by three, and you get 3x+4/5x. after that you bring the 5x up into the top of the fraction, but you have to make it negative. so your problem should look like 3x+4-5x. add the common numbers, (3x-5x) and that gives you -2x+4 as your final answer!!