13 / 15m - 3/4m+1/12m при m=2 целых 1/2 и 6 целых 1/4

Упростим:

13/15m - 3/4m + 1/12m = 13/15m - (3 * 3) / (4 * 3) m + 1/12m = 13/15m - 9/12m + 1/12m = 13/15m + (-9 + 1) / 12m = 13/15m - 8/12m = 13/15m - (4 * 2) / (4 * 3) m = 13/15m - 2/3m = 13/15m - (2 * 5) / (3 * 5) m = 13/15m - 10/15m = (13 - 10) / 15m = 3/15m = 3 / (3 * 5) m = 1/5m.

Найдем значение выражения, если m = 2 1/2:

1/5 * 2 1/2 = 1/5 * (2 * 2 + 1) / 2 = 1/5 * (4 + 1) / 2 = 1/5 * 5/2 = (1 * 5) / (5 * 2) = 1/2.

Найдем значение выражения, если m = 6 1/4:

1/5 * 6 1/4 = 1/5 * (6 * 4 + 1) / 4 = 1/5 * (24 + 1) / 4 = 1/5 * 25/4 = (5 * 5) / (5 * 4) = 5/4 = 1 1/4.