According to the concept of reciprocal, the product of a number and its reciprocal = 1. For example, the reciprocal of 5 is 1/5, and its product is 1, then the product of a number and its reciprocal plus x gets 20, and x is 19.

The reciprocal of a number is two fifths, and this number is five fifths, so five fifths plus five eighths equals 4110.