решить -7/18-5/12=; 4целых 5/9+ (-3 целых7/15) - (-2целых3/5)=

-7/18 - 5/12 = -14/36 - 15/36 = -29/36

4 5/9 + (-3 7/15) - (-2 3/5) = 4 5/9 - 3 7/15 + 2 3/5 = 1 4/45 + 2 3/5 = 3 31/45