Question

y $= {0,8(3)+[0,1(6)-0,(4)+0,08(3)]: \frac{7}{3} }  * \frac{7}{20} + \frac{19}{80}$

Answer 1

0,8(3)=(83-8)/90=75/90=15/18=5/6
0,1(6)=(16-1)/90=15/90=3/18=1/6
0,(4)=4/9
0,08(3)=(83-8)/900=75/900=15/180=5/60=1/12
y=5/6+[1/6-4/9+1/12]:7/3·7/20+19/80
Y=5/6+[(1·6-4·4+1·3)/36]:49/60+19/80
Y=5/6+[(6-16+3)/36]:49/60+19/80
Y=5/6-7/36·60/49+19/80
Y=5/6-1/3·5/7+19/80
Y=5/6-5/21+19/80
Y=(5·280-5·80+19·21)/1680
Y=(1400-400+399)/1680
Y=1399/1680
Y=0,8327(380952)