to solve that equation you have there 2x/5 - x/3 =5
first thing you do is (me personally i dont like fractions so i will eliminate the fractions by multiplying the demonator)
3(2x/5 - x/3) = 3(5)
6x/5 - x = 15
now i do the same thing with the other fraction
5(6x/5 -x) = 5(15)
6x-5x=75
combin like terms 6x - 5x is just 1x
1x=75 divide each side by 1
x=75