把1,2,3,4,5,6,7,8,9,10填进等式中,使等式成立,数字不能重复我会三种...答:10-9=8-7=6-5=4-3=2-1
将0,1,2,3,4,5,6,7,8,9这10个数字,不遗漏,不重复地分别填入括号里,组 ...答:a=(1/2+1/3+1/4+1/5+1/6+1/7)*10/9 (找最小公倍数)=[(210/420)+(140/420)+(105/420)+(84/420)+(70/420)+(60/420)]*(10/9)=(669/420)*(10/9)=669/378 =1.7698 所以,a的整数部分是 1 或,a=(1/2+1/3+1/4+1/5+1/6+1/7)*10/9 (把分式变成小数...