用简便方法计算:2+4+6+8+10+12+14+16+18+20
问题描述:
用简便方法计算:2+4+6+8+10+12+14+16+18+20
答
(2+18)+(4+16)+(6+14)+(8+12)+10+20
用简便方法计算:2+4+6+8+10+12+14+16+18+20
(2+18)+(4+16)+(6+14)+(8+12)+10+20