Toán 1/3+1/15+1/35+1/63+1/99+1/143+1/195 = mấy ạ mong các bạn trả lời 06/10/2021 By Autumn 1/3+1/15+1/35+1/63+1/99+1/143+1/195 = mấy ạ mong các bạn trả lời
1/3+1/15+1/35+1/63+1/99+1/143+1/195 =1/1.3+1/3.5+1/5.7+1/7.9+1/9.11+1/11.13+1/13.15 =1/2.(1-1/3+1/3-1/5+…..+1/13-1/15) =1/2.(1-1/15) =1/2.14/15 =14/30=7/15 Trả lời
1/3+1/15+1/35+1/63+1/99+1/143+1/195
=1/1.3+1/3.5+1/5.7+1/7.9+1/9.11+1/11.13+1/13.15
=1/2.(1-1/3+1/3-1/5+…..+1/13-1/15)
=1/2.(1-1/15)
=1/2.14/15
=14/30=7/15
Đáp án:
Giải thích các bước giải: