When x is subtracted from each of the numbers 54, 49, 22 and 21, the numbers so obtained are in proportion. The ratio of (8x - 25) to (7x - 26) is:

29 : 24

The proportion is

54 - x : 49 - x :: 22 - x : 21 - x 

Then, Product of the middle terms = product of extremes 

(49 - x)(22 - x) = (54 - x)(21 - x) 

1078 - 49x - 22x + x² = 1134 - 54x -21x + x²

Solving, x = 14 

(8x - 25) : (7x - 26) = (8 x 14 - 25) : (7 x 14 - 26)

(112 - 25) :(98 - 26) 

87 : 72 = 29 : 24