-99又18分之17乘于9用简便方法算怎么算

-99Y17/18*9 =-(99+17/18)*9 =-(99*9+17/18*9) =-(99*10-99+17/2) =-(990-99+8.5) =-(990-100+1+8.5) =-(890+9.5) =-899.5