-99又28分之25乘7

问题描述:

-99又28分之25乘7

原式=-(99+25/28)×7=-[(100-1)×7+25×7/28]=-[(700-7)+25/4]
=-(693+6+1/4)=-(699+1/4)

-(99+25/28)×7=-(99×7+25×7/28)=-(99×7+25/4)=-(693+25/4)
=-(699+1/4).也就是-699又4分之1