Пошаговое объяснение:
3) 2/5 ·6/13 +1/4 ·6/13=6/13 ·(2/5 +1/4)=6/13 ·(8/20 +5/20)=6/13 ·13/20=3/10=0,3
4) 3 3/4 ·2/5 -3 6/25 ·5/27=15/4 ·2/5 -81/25 ·5/27=3/2 -3/5=1,5-0,6=0,9
5) 3/5 -3/5 ·2/7=3/5 ·(1 -2/7)=3/5 ·(7/7 -2/7)=3/5 ·5/7=3/7
6) 1/7 ·1/8 +1/7 ·1/6=1/7 ·(1/8 +1/6)=1/7 ·(3/24 +4/24)=1/7 ·7/24=1/24
Пошаговое объяснение:
3) 2/5 ·6/13 +1/4 ·6/13=6/13 ·(2/5 +1/4)=6/13 ·(8/20 +5/20)=6/13 ·13/20=3/10=0,3
4) 3 3/4 ·2/5 -3 6/25 ·5/27=15/4 ·2/5 -81/25 ·5/27=3/2 -3/5=1,5-0,6=0,9
5) 3/5 -3/5 ·2/7=3/5 ·(1 -2/7)=3/5 ·(7/7 -2/7)=3/5 ·5/7=3/7
6) 1/7 ·1/8 +1/7 ·1/6=1/7 ·(1/8 +1/6)=1/7 ·(3/24 +4/24)=1/7 ·7/24=1/24