Question

x/2+x/6+x/12+x/20+x/30+x/42+x/56=7/8

Answer 1

x/1*2+x/2*3+x/3*4+x/4*5+x/5*6+x/6*7+x/7*8=7/8

x(1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7+1/7*8)=7/8

x(1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8)=7/8

x(1-1/8)=7/8

x(7/8)=7/8

x=1