1/(x+10)(x+11)+1/(x+11)(x+12)+1/(x+12)(x+13)+1/x
题目
1/(x+10)(x+11)+1/(x+11)(x+12)+1/(x+12)(x+13)+1/x
13=1/14
答案
1/(x+10)(x+11)+1/(x+11)(x+12)+1/(x+12)(x+13)+1/(x+13)=1/14
∴1/(x+10)-1/(x+11)+1/(x+11)-1/(x+12)+1/(x+12)-1/(x+13)+1/(x+13)=1/14
∴1/(x+10)=1/14
∴x=4
举一反三
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点