Question

计算下面各题，能简便的要用简便方法计算。15点7-括号5点7一2点8、9分之4一16分之7乘以9分之4、括号4分之3一7

Answer 1

15.7 - ( 5.7 - 2.8 ) = 15.7 - 5.7 + 2.8 = 12.8

4/9 - 7/16 * 4/9 = 4/9 * 1 - 7/16 * 4/9 = 4/9 * (1 - 7/16) = 4/9 * 9/16 = 1/4

（3/4 - 5/7 ）/ (1/56) =( 3/4 / 1/56 ) - ( 5/7 /1/56 ) = 42 - 40 = 2

望采纳