(х+4.9/11)-5.6/11=1.8/11
х+4.9/11=1.8/11+5.6/11
х+4.9/11=6.14/11
х+4.9/11=7.3/11
х=7.3/11-4.9/11
х=(7-4)+(3/11-9/11)
х=3.3-9/11
х=2.11+3-9/11
х=2.5/11
проверяем
(2.5/11+4.9/11)-5.6/11=1.8/11
13.2/9-(7.5/9+у)=3.5/9
7.5/9+у=13.2/9-3.5/9
7.5/9+у=(13-3)+(2/9-5/9)
7.5/9+у=10.2-5/9
7.5/9+у=9.9+2-5/9
7.5/9+у=9.6/9
у=9.6/9-7.5/9
у=2.1/9
проверяем
13.2/9-(7.5/9+2.1/9)=3.5/9
1) 5,4*1,9=10,26
2) 10,26-2,15=8,11
Ответ:
Пошаговое объяснение:
1 9/35:(1 1/5+2/3)= 1 9/35 : ( 1 3/15 + 10/15) = 1 9/35 : 1 13/15 = 44/35 * 15/28 = 33/49
1)109 мин
2)70 мин
3)90 мин