Let us take some examples:

Ex1: 1/3 + x = 1/5

=> x = 1/5 - 1/3

=> x = (3*1 - 5*1)/15            { LCM(3, 5) = 15 }

=> x = (3 - 5)/15

=> x = -2/15

Ex2: 5x/3 - 4 = 2x/5

=> 5x/3 = 2x/5 + 4

=> 5x/3 - 2x/5 = 4

=> (5x * 5 - 2x * 3)/15 = 4    { LCM(3, 5) = 15 }

=> (25x - 6x)/15 = 4

=> 19x/15 = 4

=> 19x = 15 * 4

=> 19x = 60

=> x = 60/15

In this way, we can solve the questions that are in fractions.