1/4+1/28+1/70+1/130.1/10300

1/4+1/28+1/70+1/130.1/10300
1/4+1/28+1/70+1/130.1/10300

1/4+1/28+1/70+1/130.1/10300
1/4+1/28+1/70+1/130.1/10300
=1/(1x4)+1/(4x7)+1/(7x10)+…+1/(100x103)
=(1/3)x[3/(1x4)+3/(4x7)+1/(7x10)+…+3/(100x103)]
=(1/3)x[(1-1/4)+(1/4-1/7)+(1/7-1/10)+…+(1/100-1/103)]
=(1/3)x(1-1/4+1/4-1/7+1/7-1/10+…+1/100-1/103)
=(1/3)x(1-1/103)
=(1/3)x(102/103)
=34/103

1/4+1/28+1/70+1/130.......1/10300
=1/1x4+1/4x7+1/7x10+1/10x13+....+1/100x103
=1/3x(1-1/4)+1/3x(1/4-1/7)++1/3x(1/7-1/10)+1/3x(1/10-1/13)+...+1/3x(1/100-1/103)
=1/3x(1-1/4+1/4-1/7+1/7-1/10+1/10-1/13+...+1/100-1/103)
=1/3x(1-1/103)
=1/3x102/103
=34/103