0,83c+0,56c-0,92c-0,83c 1/4m-1/3m+1/2m-1/6m -2/3y-5/21+1/7y+5/21y 8a+14b-9a-15b+7a-8a тоже: подобные слагаемые,реши : )

0,83c+0,56c-0,92c-0,83c = -0,36c

1/4m-1/3m+1/2m-1/6m = 3/12m - 4/12m + 6/12m - 2/12m = 3/12m = 1/4m

-2/3y-5/21+1/7y+5/21y = -14/21y - 5/21 + 3/21y + 5/21y = -6/21y - 5/21 = -2/7y - 5/21

8a+14b-9a-15b+7a-8a = -2a - b