B=1/1.5+1/5.9+1/9.13+1/13.17+1/17.19 giúp mik với mik cần gấp ak

1 bình luận về “B=1/1.5+1/5.9+1/9.13+1/13.17+1/17.19 giúp mik với mik cần gấp ak”

1. ~Ly~

   1/(1.5)+1/(5.9)+(1/9.13)+1/(13.17)+(1/17.19)

   =1/4(1/1-1/5)+1/4(1/5-1/9)+1/4(1/9-1/13)+1/4(1/13-1/17)+1/2(1/17-1/19)

   =1/4(1/1-1/5+1/5-1/9+1/9-1/13+1/13-1/17)+1/2(1/17-1/19)

   =1/4(1-1/17)+1/2 . 2/323

   =1/4 . 16/17+1/323

   =4/17+1/323

   =77/323

   Trả lời