A)
7/12m + 5/9n - 1 1/2m - 2/3n =
(7/12 - 1 1/2)*m + (5/9 - 2/3)*n =
(7/12 - 3/2)*m + (5/9 - 6/9)*n =
(7/12 - 18/12)*m + (-1/9)*n =
-11/12m - 1/9n или -(11/12m + 1/9n),
Б)
-p + 1,02g - 23/25g - 2,5p + 1 1/8p =
(-1 - 2,5 + 1 1/8)*p + (1,02 - 23/25)*g =
(-1 - 2,5 + 1,125)*p + (1,02 - 0,92)*g =
-2,375p + 0,1g