1. The problem statement, all variables and given/known data 3. The attempt at a solution I don't understand in step one why the three in the numerator disappears. I also don't understand why dy/dx becomes d/dx. the book just says left side is d/dx(v*y), a lot of help that is. how do you go to two fractions with x^3 and x^4 to one fraction with x^3 in the numerator. In step 3 they integrate both sides, but I don't see any integration of the left side. I have a feeling that they are moving the d/dx to the right side, if so, what happens to the d?