[8分之1+24分之1+48分之1+80分之1+120分之1+168分之1+224分之1]*64 写出详细过程

[8分之1+24分之1+48分之1+80分之1+120分之1+168分之1+224分之1]*64
=1/2*（1/2-1/4+1/4-1/6+1/6-1/8+1/8-1/10+1/10-1/12+1/12-1/14+1/14-1/16）*64
=1/2*（1/2-1/16）*64
=1/2*7/16*64
=7/32*64
=14

[1/8+1/24+1/48+1/80+1/120+1/168+1/224]*64
=[1+1/3+1/6+1/10+1/15+1/21+1/28]*8
=[1+1/3+1/(2*3)+1/(2*5)+1/(3*5)+1/(3*7)+1/(4*7)]*8
=[3*4*5*7+4*5*7+2*5*7+2*3*7+4*7+4*5+3*5]*8/(3*4*5*7)
=[420+140+70+42+28+20+15]*2/(3*5*7)
=735*2/(3*5*7)
=14

=8(1+1/3+1/6+1/10+1/15+1/21+1/28)
=16(2+1/6+1/12+1/20+1/30+1/42+1/56)
=32+16[1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+1/(6*7)+1/(7*8)]
=32+16[ (1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+(1/6-1/7)+(1/7-1/8)]
=32+16(1/2-1/8)
=32+8-2
=38