f(x)=2x/1+2x =4x
f(1)+f(2).+f(100)=4(1+2+3……100）=4(1+100)*100/2
f(1/2)+f(2/2).+f(100/2)=4(1/2+2/2+3/2+100/2)=4(1/2+100/2)*100/2
f(1/3)+f(2/3).+f(100/3)=4(1/3+2/3+3/3+100/3)=4(1/3+100/3)*100/2
f(1/4)+f(2/4).+f(100/4)=4(1/4+2/4+3/4+100/4)=4(1/4+100/4)*100/2
s=4*100/2*(1+1/2+1/3+1/4……1/100)+4*100/2(100/1+100/2+100/3+100/4……100/100)
=200*(1+1/2+1/3+1/4……1/100)+200*100(1+1/2+1/3+1/4……1/100)
=(200+200*100)*(1+1/2+1/3+1/4……1/100)
1+1/2+1/3+1/4+.+1/100 =1/1*2+1/2*3+1/3*4+.+1/99*100
=（1-1/2）＋（1/2-1/3）+（1/3-1/4）＋...＋（1/99-1/100）
＝1-1/100
＝99/100
s=[200+200*100]*(99/100)=202*99=19998