Если (27/31)+(75/41)+(144/51)=a, то чему равно (4/31)+(7/41)+(9/51) ?

(27/31) + (75/41) + (144/51) = a

4/31 = 31/31 - 27/31 = 1 - 27/31

7/41 = 82/41 - 75/41 = 2 - 75/41

9/51 = 153/51 - 144/51 = 3 - 144/51

(4/31) + (7/41) + (9/51) = 1 - 27/31 + 2 - 75/41 + 3 - 144/51 = 1 + 2 + 3 - (27/31 + 75/41 + 144/51) = 6 - a