\(A=\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{999.1000}\)
\(B=\frac{1}{501.1000}+\frac{1}{502.999}+...+\frac{1}{999.502}+\frac{1}{1000.501}\)
Tính\(\frac{A}{B}\)?
Mk cần gấp nhanh lên nhé!
A = 1/1.2 +1/3.4+ ...1/999.1000
B=1/501.1000 + 1/502.999+... + 1/999.502 + 1/1000.501
tính A/B
Chứng minh rằng:
a)\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}< \frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{99.100}\)
b)\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{99.100}< 1-\frac{1}{2.3}\)
Cần gấp, ai nhanh mik tick nha
Ai giúp đi, làm ơnnnnnnnnnnnnnnnnnnn
\(B=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{99}-\frac{1}{100}\)
\(B=1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}-2.\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{100}\right)\)
\(B=1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{100}-\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{50}\right)\)
\(B=\frac{1}{51}+\frac{1}{52}+...+\frac{1}{100}\)
\(B< \frac{1}{60}+\frac{1}{60}+...+\frac{1}{60}\)
\(B< \frac{50}{60}\Leftrightarrow B< \frac{5}{6}\)
Tính: \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+..........+\frac{1}{997.998}+\frac{1}{999.1000}\)
Đặt Q = \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{997.998}+\frac{1}{999.1000}\)
Đặt A = \(\frac{1}{1.3}+\frac{1}{3.5}+...+\frac{1}{997.999}\)
\(2A=1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{997}-\frac{1}{999}\)
\(2A=1-\frac{1}{999}\)
\(2A=\frac{998}{999}\)
\(\Leftrightarrow A=\frac{499}{999}\)
Đặt B = \(\frac{1}{2.4}+\frac{1}{4.6}+...+\frac{1}{998.1000}\)
\(2B=\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+...+\frac{1}{998}-\frac{1}{1000}\)
\(2B=\frac{1}{2}-\frac{1}{1000}\)
\(B=\frac{499}{1000}\)
Vậy Q = A + B = \(\frac{499}{999}+\frac{499}{1000}\)
Tính: \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+.......+\frac{1}{997.998}+\frac{1}{999.1000}\)
\(\frac{1}{1.2}+\frac{1}{2.3}+...........+\frac{1}{999.1000}\)
\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+..........+\frac{1}{999}-\frac{1}{1000}\)
\(=1-\frac{1}{1000}=\frac{999}{1000}\)
Đặt
\(A=\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{999.1000}\)
\(\Leftrightarrow A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{999}-\frac{1}{1000}\)
\(\Leftrightarrow A=1-\frac{1}{1000}\)
\(\Leftrightarrow A=\frac{999}{1000}\)
Đặt:
\(A=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{99.100}\)
\(\Leftrightarrow A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\)
\(\Leftrightarrow A=1-\frac{1}{100}\)
\(\Leftrightarrow A=\frac{99}{100}\)
Tính: \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+.....+\frac{1}{997.998}+\frac{1}{999.1000}\)
Đặt biểu thức là A.
A=\(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{999}-\frac{1}{1000}\)
A=\(\frac{1}{1}-\frac{1}{1000}\)
A=\(\frac{999}{1000}\)
Tính: \(D=\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+......+\frac{1}{999.1000}\)
Bài 1 :
Cho :
A = \(\frac{1}{51}\)+ \(\frac{1}{52}\)+ . . . + \(\frac{1}{100}\)
B = 1 - \(\frac{1}{2}\)+ \(\frac{1}{3}\)- \(\frac{1}{4}\)+ ... + \(\frac{1}{99}\)- \(\frac{1}{100}\)
C = \(\frac{1}{1.2}\)+ \(\frac{1}{3.4}\)+ \(\frac{1}{5.6}\)+ . . . + \(\frac{1}{99.100}\)
So sánh A với B với C
Bài 2 :
Cho :
A = \(\frac{1}{1.2}\)+\(\frac{1}{3.4}\)+ . . . + \(\frac{1}{999.1000}\)
B = \(\frac{1}{501.1000}\)+ \(\frac{1}{502.999}\)+ . . . +\(\frac{1}{999.502}\)+ \(\frac{1}{1000.501}\)
Tính \(\frac{A}{B}\)= ?
Bài 3 : Tính
a) A = \(\frac{3}{4}\).\(\frac{8}{9}\). \(\frac{15}{16}\). ... . \(\frac{9999}{10000}\)
b) B = \(\frac{8}{9}\). \(\frac{15}{16}\). \(\frac{24}{25}\). ... . \(\frac{3599}{3600}\)
Bài 4 :
Cho : A =\(\frac{1}{2}\).\(\frac{3}{4}\). \(\frac{5}{6}\). ... . \(\frac{9999}{10000}\)
B = \(\frac{1}{100}\)
So sánh A và B
Bài 1 :
Cho :
A = \(\frac{1}{51}\) + \(\frac{1}{52}\) + . . . + \(\frac{1}{100}\)
B = 1 - \(\frac{1}{2}\) + \(\frac{1}{3}\)- \(\frac{1}{4}\) + ... + \(\frac{1}{99}\)- \(\frac{1}{100}\)
C = \(\frac{1}{1.2}\) + \(\frac{1}{3.4}\) + \(\frac{1}{5.6}\)+ . . . + \(\frac{1}{99.100}\)
So sánh A với B với C
Bài 2 :
Cho :
A = \(\frac{1}{1.2}\) +\(\frac{1}{3.4}\) + . . . + \(\frac{1}{999.10000}\)
B = \(\frac{1}{501.1000}\) + \(\frac{1}{502.999}\) + . . . +\(\frac{1}{999.502}\) + \(\frac{1}{1000.501}\)
Tính \(\frac{A}{B}\) = ?
bài 2:
a)\(A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{999}-\frac{1}{1000}\)
\(=1-\frac{1}{1000}\)
\(=\frac{999}{1000}\)
mk ko biết bn có sai đề ko nhưng mk chỉ lm theo ý mk hiểu thôi! sai thì thôi nha!
Bài 1 :
Cho :
A = \(\frac{1}{51}\) + \(\frac{1}{52}\) + . . . + \(\frac{1}{100}\)
B = 1 - \(\frac{1}{2}\) + \(\frac{1}{3}\)- \(\frac{1}{4}\) + ... + \(\frac{1}{99}\)- \(\frac{1}{100}\)
C = \(\frac{1}{1.2}\) + \(\frac{1}{3.4}\) + \(\frac{1}{5.6}\)+ . . . + \(\frac{1}{99.100}\)
So sánh A với B với C
Bài 2 :
Cho :
A = \(\frac{1}{1.2}\) +\(\frac{1}{3.4}\) + . . . + \(\frac{1}{999.10000}\)
B = \(\frac{1}{501.1000}\) + \(\frac{1}{502.999}\) + . . . +\(\frac{1}{999.502}\) + \(\frac{1}{1000.501}\)
Tính \(\frac{A}{B}\) = ?
bn làm như vầy nè
a=1/51+1/52+...+1/100
A=1/3.1/7 + 1/2.1/26+....1/2.1/50
A=1/3-1/7+1/2-1/26+...1/2-1/50
A=1/3-1/50
A=47/50
như vầy đó bn tin mik đi