9+99+999+9999+99999=?89999999+8999998+899997+89996+8995+894=?请用简便_数学解答

9+99+999+9999+99999=?
89999999+8999998+899997+89996+8995+894=?
请用简便算法计算,

人气：445 ℃　时间：2020-05-10 22:40:16

解答

(1+11+111+1111+11111)x9=111105
(90000000+9000000+900000+90000+9000+900)-(1+2+3+4+5+6)=999879