Пошаговое объяснение:
1.
4*(5/9) + 2/9 = 41/9 + 2/9 = 43/9 = 4*(7/9)
3*(5/21) + 4(8/21) = (3+4) + (5/21 + 8/21) = 7 + 13/21 = 7*(13/21)
3+12*(11/12) = 3 + 12 + 11/12 = 15 + 11/12 = 15*(11/12)
9*(5/6) + 7 = 9 + 5/6 + 7 = 16+ 5/6 = 16*(5/6)
7*(15/19)+4*(14/19) = (7+4) + (15/19 + 14/19) = 11 + 29/19 = 11 + 1*(10/19) = 12 + 10/19 = 12*(10/19)
3*(12/23) + 4(11/23) = (3+4) + (12/23 + 11/23) = 7 + 1 = 8
2.
4*(14/19) - 2*(5/19) = (4-2) + (14/19 - 5/19) = 2+9/19 = 2*(9/19)
8*(8/10) - 5 = 87/10 - 5 = 37/10
8*(7/15) - 3*(11/15) = 127/15 - 56/15 = 71/15
10*(9/14) - 3*(9/14) = (10-3) + (9/14 - 9/14) = 7
12-7/18 = 216-7/18 = 209/18
11-3*(5/12) = 11-41/12 = 91/12
3.
11/27+13/27-8/27 = 11+13-8/27 = 16/27
18/19 - (8/19 + 7/19) = 18/18 - 15/19 = 3/19