(4/9-5/12+0,75)*3/7 решение
4/9-5/12=16/36-15/36=1/362) 1/36+0,75=1/36+75/100=100/3600+2700/3600=2800/3600=7/93) 7/9*3/7=21/63=1/3
1 действие) 4/9-5/12=16/36-15/36=1/362) 1/36+0,75=1/36+75/100=100/3600+2700/3600=2800/3600=7/93) 7/9*3/7=21/63=1/3Ответ:1/3