Ta có
B = (1 + 1/9).(1 + 1/15).(1 + 1/24)...(1 + 1/440).(1 + 1/483)
Mà 1 + 1/9 = 10/9 = (32 + 1)/32 = 1 + (1/32)
1 + 1/15 = 16/15
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Các câu hỏi tương tự
Tính nhanh theo mẫu:
Mẫu: Bleft(1+dfrac{1}{3}right)x left(1+dfrac{1}{8}right)x left(1+dfrac{1}{15}right)x left(1+dfrac{1}{24}right)x ..... x left(1+dfrac{1}{120}right)x left(1+dfrac{1}{413}right)
Bleft(dfrac{3}{3}+dfrac{1}{3}right)x left(dfrac{8}{8}+dfrac{1}{8}right)x left(dfrac{15}{15}+dfrac{1}{15}right)x left(dfrac{24}{24}+dfrac{1}{24}right)x........xleft(dfrac{120}{120}+dfrac{1}{120}right)x left(dfrac{143}{143}+dfrac{1}{143}right)
Bdfrac{4}{3}xdfrac{9}{8}xdfrac{16}{15}xdfrac{25}{24}x.........
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Tính nhanh theo mẫu:
Mẫu: \(B=\left(1+\dfrac{1}{3}\right)\)x \(\left(1+\dfrac{1}{8}\right)\)x \(\left(1+\dfrac{1}{15}\right)\)x \(\left(1+\dfrac{1}{24}\right)\)x ..... x \(\left(1+\dfrac{1}{120}\right)\)x \(\left(1+\dfrac{1}{413}\right)\)
\(B=\left(\dfrac{3}{3}+\dfrac{1}{3}\right)\)x \(\left(\dfrac{8}{8}+\dfrac{1}{8}\right)\)x \(\left(\dfrac{15}{15}+\dfrac{1}{15}\right)\)x \(\left(\dfrac{24}{24}+\dfrac{1}{24}\right)\)x........x\(\left(\dfrac{120}{120}+\dfrac{1}{120}\right)\)x \(\left(\dfrac{143}{143}+\dfrac{1}{143}\right)\)
\(B=\dfrac{4}{3}\)x\(\dfrac{9}{8}\)x\(\dfrac{16}{15}\)x\(\dfrac{25}{24}\)x.......x\(\dfrac{121}{120}\)x \(\dfrac{144}{143}\)
\(B=\dfrac{2x2}{1x3}\)x\(\dfrac{3x3}{2x4}\)x\(\dfrac{4x4}{3x5}\)x\(\dfrac{5x5}{4x6}\)x.......x\(\dfrac{11x11}{10x12}\)x\(\dfrac{12x12}{13x11}\)
\(B=\dfrac{2x3x4x5x......x10x11x12}{1x2x3x......x10x11x12}\)x \(\dfrac{2x3x4x5x....x11x12}{3x4x5x6x......x12x13}\)
B= \(\dfrac{12}{1}\)x\(\dfrac{2}{13}\)
B=\(\dfrac{24}{13}\)
Câu hỏi:
\(B=\left(1+\dfrac{1}{8}\right)\)x\(\left(1+\dfrac{1}{15}\right)\)x\(\left(1+\dfrac{1}{24}\right)\)x..... x \(\left(1+\dfrac{1}{440}\right)\)x \(\left(1+\dfrac{1}{483}\right)\)
Tính nhanh:
\(A=\left(1-\dfrac{1}{9}\right)\)x \(\left(1-\dfrac{1}{16}\right)\)x \(\left(1-\dfrac{1}{25}\right)\)x.......... x \(\left(1-\dfrac{1}{361}\right)\)x \(\left(1-\dfrac{1}{400}\right)\)
tìm x:
a,\(\left(\dfrac{1}{1.2}+\dfrac{1}{2.3}+...+\dfrac{1}{9.10}\right).\left(x-1\right)+\dfrac{1}{10}.x=x-\dfrac{9}{10}\)
b,\(\left(\dfrac{1}{1.3}+\dfrac{1}{3.5}+\dfrac{1}{5.7}+...+\dfrac{1}{97.99}\right).\left(x-2\right)+x=\dfrac{149}{99}.x-\dfrac{98}{99}\)
Tìm x:
a)2016x+left(dfrac{7}{12}+dfrac{4}{21}+dfrac{2}{24}+dfrac{11}{30}+dfrac{3}{40}+dfrac{15}{56}right)-left(dfrac{2}{3}+dfrac{2}{4}+dfrac{2}{5}right)0
bdfrac{2x-1}{x+2015}-dfrac{4025}{x+2017}dfrac{x-2014}{2x-4036}-dfrac{x-2013}{2x-4030} (x thuộc N)
c)left(1+dfrac{1}{1.3}right)left(1+dfrac{1}{2.4}right)left(1+dfrac{1}{3.5}right)...left(1+dfrac{1}{xleft(x+2right)}right)dfrac{4016}{2007}
AI GIÚP MK VỚI MK TICK CHO
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Tìm x:
a)\(2016x+\left(\dfrac{7}{12}+\dfrac{4}{21}+\dfrac{2}{24}+\dfrac{11}{30}+\dfrac{3}{40}+\dfrac{15}{56}\right)-\left(\dfrac{2}{3}+\dfrac{2}{4}+\dfrac{2}{5}\right)=0\)
b\(\dfrac{2x-1}{x+2015}-\dfrac{4025}{x+2017}=\dfrac{x-2014}{2x-4036}-\dfrac{x-2013}{2x-4030}\) (x thuộc N)
c)\(\left(1+\dfrac{1}{1.3}\right)\left(1+\dfrac{1}{2.4}\right)\left(1+\dfrac{1}{3.5}\right)...\left(1+\dfrac{1}{x\left(x+2\right)}\right)=\dfrac{4016}{2007}\)
AI GIÚP MK VỚI MK TICK CHO 
Bài 1: Tìm x, biết:
a, left(x+dfrac{1}{4}-dfrac{1}{3}right):left(2+dfrac{1}{6}-dfrac{1}{4}right)dfrac{7}{46}
b, dfrac{13}{15}-left(dfrac{13}{21}+xright).dfrac{7}{12}dfrac{7}{10}
Bài 2: Thực hiện phép tính:
a, left(2dfrac{5}{6}+1dfrac{4}{9}right):left(10dfrac{1}{12}-9dfrac{1}{2}right)
b, 1dfrac{5}{18}-dfrac{5}{18}.left(dfrac{1}{15}+1dfrac{1}{12}right)
c, -dfrac{1}{7}.left(9dfrac{1}{2}-8,75right):dfrac{2}{7}+0,625:1dfrac{2}{3}
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Bài 1: Tìm x, biết:
a, \(\left(x+\dfrac{1}{4}-\dfrac{1}{3}\right):\left(2+\dfrac{1}{6}-\dfrac{1}{4}\right)=\dfrac{7}{46}\)
b, \(\dfrac{13}{15}-\left(\dfrac{13}{21}+x\right).\dfrac{7}{12}=\dfrac{7}{10}\)
Bài 2: Thực hiện phép tính:
a, \(\left(2\dfrac{5}{6}+1\dfrac{4}{9}\right):\left(10\dfrac{1}{12}-9\dfrac{1}{2}\right)\)
b, 1\(\dfrac{5}{18}-\dfrac{5}{18}.\left(\dfrac{1}{15}+1\dfrac{1}{12}\right)\)
c, \(-\dfrac{1}{7}.\left(9\dfrac{1}{2}-8,75\right):\dfrac{2}{7}+0,625:1\dfrac{2}{3}\)
tìm x biết
left(3dfrac{1}{2}+2xright).2dfrac{2}{3}5dfrac{1}{3}
dfrac{3}{4}-2.left|2x-dfrac{2}{3}right|2
left(0.6-dfrac{1}{2}right).dfrac{3}{4}-left(-1right)dfrac{1}{3}
left(3x-1right).left(-dfrac{1}{2}x+5right)0
dfrac{1}{4}+dfrac{1}{3}:left(2x-1right)-5
left(2x+dfrac{3}{5}right)^2-dfrac{9}{25}0
-5.left(x+dfrac{1}{5}right)-dfrac{1}{2}.left(x-dfrac{2}{3}right)dfrac{3}{2}x-dfrac{5}{6}
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tìm x biết
\(\left(3\dfrac{1}{2}+2x\right).2\dfrac{2}{3}=5\dfrac{1}{3}\)
\(\dfrac{3}{4}-2.\left|2x-\dfrac{2}{3}\right|=2\)
\(\left(0.6-\dfrac{1}{2}\right).\dfrac{3}{4}-\left(-1\right)=\dfrac{1}{3}\)
\(\left(3x-1\right).\left(-\dfrac{1}{2}x+5\right)=0\)
\(\dfrac{1}{4}+\dfrac{1}{3}:\left(2x-1\right)=-5\)
\(\left(2x+\dfrac{3}{5}\right)^2-\dfrac{9}{25}=0\)
\(-5.\left(x+\dfrac{1}{5}\right)-\dfrac{1}{2}.\left(x-\dfrac{2}{3}\right)=\dfrac{3}{2}x-\dfrac{5}{6}\)
Tìm x, biết :
a) left(dfrac{31}{20}-dfrac{26}{45}right).dfrac{-36}{35} x left(dfrac{51}{56}+dfrac{8}{21}+dfrac{1}{3}right).dfrac{8}{13}
b) dfrac{-3}{5}.xdfrac{1}{4}+0,75
c) left(dfrac{1}{7}-dfrac{1}{3}right).xdfrac{28}{3}.left(dfrac{1}{4}-dfrac{1}{7}right)
d) dfrac{5}{7}.xdfrac{9}{8}-0,125
e)left(dfrac{2}{11}+dfrac{1}{3}right).xleft(dfrac{1}{7}-dfrac{1}{8}right).56
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Tìm x, biết :
a) \(\left(\dfrac{31}{20}-\dfrac{26}{45}\right).\dfrac{-36}{35}< x< \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}\)
b) \(\dfrac{-3}{5}.x=\dfrac{1}{4}+0,75\)
c) \(\left(\dfrac{1}{7}-\dfrac{1}{3}\right).x=\dfrac{28}{3}.\left(\dfrac{1}{4}-\dfrac{1}{7}\right)\)
d) \(\dfrac{5}{7}.x=\dfrac{9}{8}-0,125\)
e)\(\left(\dfrac{2}{11}+\dfrac{1}{3}\right).x=\left(\dfrac{1}{7}-\dfrac{1}{8}\right).56\)
tìm x biết
a) \(\dfrac{2x-3}{3}+-\dfrac{3}{2}=\dfrac{5-2x}{6}-\dfrac{1}{2}\)
b) \(\left(3x-\dfrac{1}{2}\right).\left(3-\dfrac{1}{2}x\right).\left(1+\dfrac{3}{4}:x\right)=0\)
c) \(\left(3-\dfrac{9}{10}-|x+2|\right):\left(\dfrac{19}{20}-1-\dfrac{2}{3}\right)+\dfrac{4}{5}=1\)
BT3: Tìm x, biết
13) \(\left(-1\dfrac{1}{5}+x\right):\left(-3\dfrac{3}{5}\right)=\dfrac{-7}{4}+\dfrac{1}{4}:\dfrac{1}{8}\)
14) \(\dfrac{11}{13}-\left(\dfrac{5}{42}-x\right)=-\left(\dfrac{15}{28}-\dfrac{11}{13}\right)\)