(20又9/4+12.25-31又30/1)÷299+9(13又9/1-12.25)×1又31/5=(9/184+4/49-30/931)×299/1+9(9/118-4/49)×31/36=[(9×20)/(184×20)+(4×45)/(49×45)-(30×6)/(931×6)]×299/1+9[(9×4)/(118×4)-(4×9)/(49×9)]×...