1/1*3+1/2*4+1/3*5+1/4*6+.+1/100*102=?

1/1*3+1/2*4+1/3*5+1/4*6+.+1/100*102=?
1/1*3+1/2*4+1/3*5+1/4*6+.+1/100*102=?

1/1*3+1/2*4+1/3*5+1/4*6+.+1/100*102=?
1/1*3+1/2*4+1/3*5+1/4*6+…+1/100*102
=（1-1/3+1/2-1/4+1/3-1/5+1/4-1/6+……+1/100-1/102）÷2
=（1+1/2-1/101-1/102）
=（3/2-203/10302）÷2
=15250/10302÷2
=7625/10302