Ответ:
1) 7/12 * 12 + 3/12 * 12 = 7 + 3 = 10
2) 4/7 * (-7) + 6/7 * (-7) = -4 -6 = -10
3) 5/6 * 6 - 1/6 * 6 = 5-1 = 4
4) 1/55 * (-11) + 5/55 * (-11) = -1/5 -5/5 = -6/5
5) 2/5 * 2 + 3/5 * 2 = 4/5 + 6/5= 10/5 = 2
6) 12/15 * (-3) - 7/15 * (-3) = -12/5 + 7/5 = -5/5 = -1
7) 40/57 * 1 + 17/57 *1 = 40/57 + 17/57 = 57/57 = 1