31又5分之1乘8.1+4.37乘19+1.9乘87又2分之1=?_数学解答

31又5分之1乘8.1+4.37乘19+1.9乘87又2分之1=?

人气：247 ℃　时间：2020-03-22 13:34:23

解答

原式
=31.2x8.1+4.37x19+1.9x87.5
=31.2x8.1+4.37x19+19x8.75
=31.2x8.1+(4.37+8.75)x19
=31.2x8.1+13.12x19
=3.12x81+(3.12+10)x19
=3.12x81+3.12x19+10x19
=3.12x(81+19)+10x19
=3.12x100+190
=312+190
=502