1. Find a four-digit integer x such that 4xis another four-digit integer whose digits are in the reverse order of the digits of x. 2. There is only one way to write 1 as a sum of the reciprocals of...

1. Find a four-digit integer x such that 4xis another four-digit integer whose digits are in the reverse order of the digits of x.

2. There is only one way to write 1 as a sum of the reciprocals of three different positive integers:

Find all possible ways to write 1 as a sum of the reciprocals of four different positive integers.