Question

вычислить 1/6*7+1/7*8+...+1/48*49+1/49*50.

Answer 1

1/6*7+1/7*8+...+1/48*49+1/49*50=
=(1/6-1/7)+(1/7-1/8)+...+(1/48-1/49)+(1/49-1/50)=
=1/6-1/50=11/75;