Решить очень срочно (3/4-8/15)+17/20=
(3/4-8/15)+17/20=13/60+17/20=16/15=1.06
(3/4 - 8/15) + 17/20 = 1 1/15,
1) 3/4 - 8/15 = 45/60 - 32/60 = 13/60,
2) 13/60 + 17/20 = 13/60 + 51/60 = 64/60 = 1 4/60 = 1 1/15