to integrate of 5/3x, you need f'(x) on the top and f(x) on the bottom, so take 5 out of the picture:
5 S 1/3x dx (S meaning the integral sign)
= 5/3 S 3/3x dx(as you need a 3 on top, you borrow a three and then divide by it)
= 5/3 ln 3x + c
hope that helps
edit*lol i think i posted this a...