1. 11/5×(1/脊晌3+1/缺慎2)×3/樱扮锋11×4/5 =2/52.-3-【-5+(1-0.2×3/5)×(-1/2)】 =61/253.-1+5×(-2)×(-1/2) =4
1: 2/52:61/253:4
(1)2/5(2)61/25(3)4