1) 4,3-3/8*2,3-5=-1 9/16 3/8*2,3=3/8*23/10=69/80 4,3-69/80=43/10-69/80=344/80-69/80=275/80=55/16=3 7/16 3 7/16-5=-1 9/16 2) 9-3,3*(1/8-1/7)=9 33/560 1/8-1/7=7/56-8/56=-1/56 3,3*(-1/56)=33/10*(-1/56)=-33/560 9-(-33/560)=9+33/560=9 33/560 3) 4 4/9*2/3*2/11:4,2=800/6237 4 4/9*2/3=40/9*2/3=80/27 80/27*2/11=160/297 160/297:4,2=160/297*5/21=800/6237
