Пошаговое объяснение:
383)
1) = 9 3/4 *(3 1/3 + 5 1/13) = 9 3/4 * (3 13/39 + 5 3/39) = 9 3/4 * 8 16/39 = 39/4 * 328/39 = 82
2) = 11 3/5 * 2 1/2 - 5 1/3 * 1 1/5 = 58/5 * 5/2 - 16/3 * 6/5 = 29 - 32/5 = 29 - 6 2/5 = 22 3/5
385)
1) = 4/9 * (6 5/8 + 2 3/8) = 4/9 * 9 = 4
2) = 7/10 * (17 4/11 - 7 4/11) = 7/10 * 10 = 7
3) = 21 9/20 * (10 4/15 + 9 11/15) = 21 9/20 * 20 = 429/20 * 20 = 429
4) = 4 3/5 * (12 13/19 - 7 13/19) = 4 3/5 * 5 = 23/5 * 5 = 23
386)
1) = 6/14a + 5/14a = 10/14a = 5/7a
2) = 14/18a - 5/18a = 9/18a = 1/2a
3) = 6 19/25c - 10/25c = 6 9/25c
4) = 5 12/12b = 6
20x+15y+21x-15y=75+48
41x=123
x=3
y=1