agato4kamagadan А)(4/7*5/3)-(4/7*4/3)=20/21-16/21=4/21
X-100%
4/21-67%
X=4*100/(21*67)=400/1407
Б)3/4*(2/3+5/3)=3/4*7/3=21/12
21/12:2/1=21/12*1/2=21/24
Х-100%
21/24-28%
Х=100*21/(24*28)=2100/672=1050/336=525/168
В)3 5/12*(2 2/9-1/6)=41/12-(20/9-1/6)=41/12(40/18-3/18)=41/12*37/18=1517/216
1517/216-100%
Х-54%
X=1517*54/(216*100)=81918/26100=40959/13050
X-100%
40959/13050 - 21%
X=40959*100/(21*13050)=4095900/274050=409590/27405=81918/5481