how could i solve this equation... x/2 + 1/15= 1/30x?

Have to assume that you mean :-

x/2 + 1/15 = (1/30) x

15 x + 2 = x

14 x = - 2

x = - 1 / 7

x/2 + 1/15 = 1/30(x)
x/2 + 1/15 = 1/30(x)
30(x/2 + 1/15) = 30(x/30)
15x + 2 = x
15x - x = -2
14x = -2
x = -2/14
x = -1/7