0.8x2/11十4.8x(一2/7)一2.2除3/7十0.8x9/11

0.8x2/11十4.8x(一2/7)一2.2除3/7十0.8x9/11
=0.8*(2/11+9/11)+24/5*(-2/7)-11/5*7/3
=0.8*1+1/5*(-48/7-77/3)
=0.8-1/5*(144/21+539/21)
=0.8-1/5*683/21
=4/5-1/5*683/21
=1/5*(4-683/21)
=1/5*(84/21-683/21)
=1/5*(-599/21)
=-599/105
=-5又74/105