1/7×102.31+40又6/7×102.

问题描述:

1/7×102.31+40又6/7×102.

1/7×102.31+40又6/7×102.31=102.31 x(1/7+286/7) =102.31 x 287/7 =102.31 x41 =102.31 x (40+1) =4092.4+102.31 =4194.71