简算：1/1*2+1/2*3+1/3*4+1/4*5+1/5*6
问题描述：
简算：1/1*2+1/2*3+1/3*4+1/4*5+1/5*6
答
1/1*2+1/2*3+1/3*4+1/4*5+1/5*6
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6
=1-1/6
=5/6