After solving the equations it gives an explanation to the problem. All I can say is it is just. And also try to improve it. Best app ever to use for math problems. Completely Satisfied. Easily the best calculator, for me math app is not all your questions can be answered but it's beautiful.
5 would work, amazing app, shows the graph, the equations, and let's me take pictures of my equations so I dont have go type it all in, at last I want to say that I am in love with this app :-).