1.Tìm tích:
a) (1/2+1).(1/3+1).(1/4+1)........(1/999+1)
b) (1/2-1).(1/3-1).(1/4-1).........(1/1000-1)
c) 3/2^2.8/3^2.15/4^2..........99/10^2
ai nhanh nhất mình tick cho
Những câu hỏi liên quan
1.Tìm tích:
a) (1/2+1).(1/3+1).(1/4+1)........(1/999+1)
b) (1/2-1).(1/3-1).(1/4-1).........(1/1000-1)
c) 3/2^2.8/3^2.15/4^2..........99/10^2
Làm giúp mình đi rồi mình tick cho
a)=3/2.4/3....1000/99=1000/2(áp dụng phương pháp triệt tiêu). b)= -1/2.-2/3.-3/4....-999/1000=-1/1000(chuyển dấu trừ).
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Tìm tích của:
a) (1/2+1).(1/3+1).(1/4+1)......(1/999+1)
b)(1/2-1).(1/3-1).(1/4-1)......(1/1000-1)
c) 3/2 mũ 2.8/3 mũ 2 . 15/4 mũ 2.....99/10 mũ 2
a,\(\left(\dfrac{1}{2}+1\right)\left(\dfrac{1}{3}+1\right)\left(\dfrac{1}{4}+1\right)...\left(\dfrac{1}{999}+1\right)\)
\(=\dfrac{3}{2}.\dfrac{4}{3}.\dfrac{5}{4}.....\dfrac{1000}{999}\)
\(=\dfrac{3.4.5....1000}{2.3.4....999}=\dfrac{1000}{2}=500\)
b,\(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)\left(\dfrac{1}{4}-1\right)...\left(\dfrac{1}{1000}-1\right)\)
\(=\dfrac{-1}{2}.\dfrac{-2}{3}.\dfrac{-3}{4}.....\dfrac{-999}{1000}\)
=\(\dfrac{-\left(1.2.3....999\right)}{2.3.4....1000}=\dfrac{-1}{1000}\)
c,\(\dfrac{3}{2^2}.\dfrac{8}{3^2}.\dfrac{15}{4^2}....\dfrac{99}{10^2}\)
\(=\dfrac{1.3}{2.2}.\dfrac{2.4}{3.3}.\dfrac{3.5}{4.4}....\dfrac{9.11}{10.10}\)
\(=\dfrac{1.3.2.4.3.5....9.11}{2.2.3.3.4.4....10.10}\)
\(=\dfrac{1.2.3...9}{2.3.4...10}.\dfrac{3.4.5...11}{2.3.4...10}\)
\(=\dfrac{1}{10}.\dfrac{11}{2}=\dfrac{11}{20}\)
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tìm tích
a/ (1/2 +1) . (1/3 +1) . (1/4 +1) ....(1/999 +1)
b/ (1/2 -1) . (1/3 -1). (1/4 -1)....(1/1000 -1)
c/ 3/2^2 .8/3^2 .15/4^2 ...99/10^2
giúp mình với nha ,mình cần gấp đó .Thanks
Nếu ko cần trình bày thì dùng Pascal mà làm
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tìm tích:
a) ( 1/2+1)*(1/3+1)*(1/4+1)*....(1/999+1)
b) (1/2-1)*(1/3-1)*(1/4-1)...(1/1000-1)
c) 3/2^2*8/3^2*15/4^2.....99/10^2
a) =3/2*4/3*5/4*....* 1000/999
=3*4*5*......*1000 / 2*3*4*...*999
=1000/2=500
phần b;c mk chưa làm đc
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Tìm tích :
a, ( 1 / 2 + 1 / 1 ) . ( 1 / 3 + 1 / 1 ) . ( 1 / 4 + 1 / 1 ) ... ( 1 / 999 + 1 / 1 )
b, ( 1 / 2 - 1 / 1 ) . ( 1 / 3 - 1 / 1 ) . ( 1 / 4 - 1 ) ... ( 1 / 1000 - 1 )
c, 3 / 22 . 8 / 32 . 15 / 42 ... 99 / 102
a. =3/2*4/3*5/4*...*1000/999
=3*4*5*....*1000/2*3*4*...*999
=1000/2
=500
b. =-1/2*-2/3*-3/4*....*-999/1000
=-1*-2*-3*.....*-999/2*3*4*....*1000
=-1/1000
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Bài3 tìm tích
a) (1/2+1).(1/3+1).(1/4+1)...(1/999+1)
b) (1/2-1).(1/3-1).(1/4-1)...(1/1000-1)
c) 3/22 .8/32 .15/42 ...99/102
a) (1/2 + 1) . (1/3 + 1). (1/4 + 1) ....(1/999 + 1)
b) (1/2 - 1) .(1/3 - 1).(1/4 - 1....(1/1000 - 1)
C) 3/2 mũ 2 .8/3 mũ 2 . 15/4 mũ 2 ....99 / 10 mũ 2
b) ...........
= 1/2x2/3x.....x999/1000
= 1x2x...x999/2x3x...x1000
=1/1000
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a) ...............
= 3/2 . 4/3 .... 1000/999
= 3x4x5x....x1000/2x3x4x...x999
=1000/2=500
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Câu 1 : (11/4.-5/9-4/9.11/4).8/33
Câu 2 : (17/28+18/29-19/30-20/31).(-5/2+1/4+1/6)
Câu 3 :(1/2+1).(1/3+1).(1/4+1) ... (1/99+1)
Câu 4 : 3/2^2.8/3^2.15/4^2 ... 899/30^2
Câu 11:
(\(\dfrac{11}{4}\). \(\dfrac{-5}{9}\) - \(\dfrac{4}{9}\).\(\dfrac{11}{4}\)).\(\dfrac{8}{33}\)
= \(\dfrac{11}{4}\).(\(\dfrac{-5}{9}\) - \(\dfrac{4}{9}\)). \(\dfrac{8}{33}\)
= \(\dfrac{11}{4}\).(-1).\(\dfrac{8}{33}\)
= - \(\dfrac{2}{3}\)
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Câu 2: (\(\dfrac{17}{28}\) + \(\dfrac{18}{29}\) - \(\dfrac{19}{30}\) - \(\dfrac{20}{31}\)).(-\(\dfrac{5}{2}\) + \(\dfrac{1}{4}\) + \(\dfrac{1}{6}\))
= (\(\dfrac{17}{28}\) + \(\dfrac{18}{29}\) - \(\dfrac{19}{30}\) - \(\dfrac{20}{31}\)).(-\(\dfrac{5}{2}\) + \(\dfrac{5}{12}\))
= (\(\dfrac{17}{28}\) + \(\dfrac{18}{29}\) - \(\dfrac{19}{30}\) - \(\dfrac{20}{31}\)). 0
= 0
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Xem thêm câu trả lời
21 tháng 8 2019 lúc 8:53
1.cho c=1/3+1/3 mũ 2 + 1/3 mũ 3 +....+1/3 mũ 98 +1/3 mũ 99. CMR c < 1/2
2.cho d=1/4+/4 mũ 2 +1/4 mũ 3 +....+1/4 mũ 999 +1/4 mũ 1000