计算1*2/1+2*3/1+3*4/+.+49*50/1
问题描述：
计算1*2/1+2*3/1+3*4/+.+49*50/1
答
1/1*2+1/2*3+1/3*4+.+1/49*50
=1-1/2+1/2-1/3+1/3-1/4+...+1/49-1/50
=1-1/50
=49/50