Find two fractions with the difference of 1/5 but with neither denominator equal to 5? i know the answer from google but how is it solved?

Suppose we try to write out this problem symbolically:

a     c      1
-- - --- = --- , b not equal to 5, d not equal to 5
b     d      5

Unfortunately, this equation contains 4 unknowns (too many)

We could do a bit of guesswork here:

a     c      1
-- - --- = --- , b not equal to 5, d not equal to 5
b     d      5

  8     6        2
--- - =
10    10      10

This is true, but not all that wonderful, because all 3 fractions could be reduced and would then have denominator 5.

The correct answer would be shape of function b = 2× slope of function a.