Question

9.8*0.1+0.5*98.1+0.049*981怎样计算简便

Answer 1

9.8*0.1+0.5*98.1+0.049*981=98×0.01+0.5×（98+0.1）+0.049×（980+1)=98×0.01+0.5×98+0.05+0.049×980+0.049=98×(0.01+0.5+0.49)+(0.05+0.049)=98+0.99=98.99