Все задания на приведение дробей к общему знаменателю.
х-3/5=3/8 х = 3/8+3/5 = 15/40+24/40 = 39/40
х-5/24=11/12 х = 11/12+5/24 = 22/24+5/24 = 27/24 = 1 3/24
х-7/12=3/4 х = 3/4+7/12 = 9/12+7/12 = 16/12 = 1 4/12 = 1 1/3
х-1/6=1/9 х = 1/9+1/6 = 2/18+3/18 = 5 /18.
3/7+1/9 = 27/63+7/63 = 34/63
3/10+1/8 = 12/40+5/40 = 17/40
7/12+4/15 = 35/60+16/60 = 51/60
3/4+5/6 = 9/12+10/12 = 19/12 = 1 7/12
2/5+3/7 = 14/35+15/35 = 29/35
9/14+2/21 = 27/42+4/42 = 31/42.