Cho A = 13/25 + 9/10 - 11/15 + 13/21 - 15/28 + 17/36 - ... + 197/4851 - 199/4950 chứng minh rằng A > 9/10
Những câu hỏi liên quan
Cho \(A=\dfrac{13}{25}+\dfrac{9}{10}-\dfrac{11}{15}+\dfrac{13}{21}-\dfrac{15}{28}+\dfrac{17}{36}-...+\dfrac{197}{4851}-\dfrac{199}{4950}\)
Chứng minh \(A>\dfrac{9}{10}\)
Cho S=13/25+9/10-11/15+13/21-15/28+17/36-.........197/4851-199/4950.Chứng minh rằng:S>9/10
Tính tổng : A=38/25 + 9/10 - 11/15 + 13/21 - 15/28 + 17/36 - ................+197/4851-199/4950
bỏ tạm 38/25 ra
=(9/10-11/15) +(13/21-15/28) +(197/4851-199/4950)
=1/6+1/12+1/20+...+1/49*50=2450
=3-2/2x3+4-3/3x4+5-4/4x5+....50-49/49x50
=1/2-1/3+1/3-...-1/50
1/2-1/50=12/25
=38/25+12/25=50/25
=2
(x-2)^2=38/25+9/10-11/15+13/21-15/28+17/36-...+197/4851-199/4950
38/25+9/10-11/15+13/21-15/28+17/36_............+197/4851-199/4950
38/25+9/10-11/15+13/21-15/28+17/36_............+197/4851-199/4950
Tìm x, biết :
(x - 2)^2 = 38/25 + 9/10 - 11/15 + 13/21 - 15/28 + 17/36 - ..... + 197/4851 - 199/4950
Tìm x:
[x-2]2=38/25+9/10-11/15+13/21-15/28+17/36-...+197/4851-199/4950
7 tháng 5 2022 lúc 14:55
A = \(\dfrac{28}{25}\) + \(\dfrac{9}{10}\) - \(\dfrac{11}{15}\) + \(\dfrac{13}{21}\) - \(\dfrac{15}{28}\) + \(\dfrac{17}{26}\) - ... + \(\dfrac{197}{4851}\) - \(\dfrac{199}{4950}\)