-486 2/2541 - (-473 1413/1694)
= -486 2/2541 + 473 1413/1694
= (-486 + 473) + (-2/2541 + 1413/1694)
= (-13) + (-2/2541 + 1413/1694)
OK, now we need to do a lot of "prime factorization":
2541 = 112*7*3
1694 = 112*7*2
The LCM of these two is:
LCM = 112*7*3*2
So ...
(-2/2541 + 1413/1694)
= (-2*2/112*7*3*2 + 1413*3/112*7*3*2)
= (4235/112*7*3*2)
Now 4235 = 112*7*5. so ....
(4235/112*7*3*2) = (112*7*5/112*7*3*2) = 5/6
So back to the original equation
= (-13) + (4235/5082)
= -13 + 5/6
= -12 1/6
Whew!