(-1/2)+(1/3)+(-1/4)+(1/9)+(1/8)+(-4/9) =

(-1/2)+(1/3)+(-1/4)+(1/9)+(1/8)+(-4/9) = 1+2+3+4、、、+8+9= 1:8 2:9 1:9 3:4 1:3 ... 数列计算 1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9=? 1/1*2*3+1/2*3*4+1/3*4*5+.+1/8*9*10 9 9 9 9=4 1 1 1 1=0 7 3 2 9=1 2 5 6 8=3 7 7 2 1=0 2 4 8 8=4 75%*8/9+3/4*1/9+0.75*9= 2/3+9/10+3/2+10/9+4/8+1+2/1= 1*1=1 1*2=2 1*3=3 1*4=4 1*5=5 1*6=6 1*7=7 1*8=8 1*9=9 for循环怎 1/9{1/7[1/5（【x+2】/3+4)+6]+8}=1 1\9{1\7[1\5(x+2\3+4)+6]+8}=1 9/1{7/1[5/1(3/x+4+2)+6]+8}=1