C ={(1+(1999/1))(1+(1999/2))(1+(1999/3))+...+(1+(1999/1000))}/{(1+(1000/1))(1+(1000/2))(1+(1000/3))...(1+(1000/1999))}
A=(1+1999/1).(1+1992/2).(1+1999/3)...(1+1999/1000)/(1+1000/1).(1+1000/2).(1+1000/3)...(1+1000/1999)
Tính A
1.Tính C=\(\frac{\left(1+\frac{1999}{1}\right)\left(1+\frac{1999}{2}\right)\left(1+\frac{1999}{3}\right)...\left(1+\frac{1999}{1000}\right)}{\left(1+\frac{1000}{1}\right)\left(1+\frac{1000}{2}\right)\left(1+\frac{1000}{3}\right)...\left(1+\frac{1000}{1999}\right)}\)
\(C=\frac{\left(1+\frac{1999}{1}\right)\left(1+\frac{1999}{2}\right)...\left(1+\frac{1999}{1000}\right)}{\left(1+\frac{1000}{1}\right)\left(1+\frac{1000}{2}\right)...\left(1+\frac{1000}{1999}\right)}\)=> \(C=\frac{\frac{2000.2001.2002....2999}{1.2.3...1000}}{\frac{1001.1002.1003....2999}{1.2.3...1999}}\)
=> \(C=\frac{\frac{2000.2001.2002....2999}{1.2.3...1000}}{\frac{\left(1001.1002.1003....1999\right).\left(2000.2001.2002...2999\right)}{\left(1.2.3...1000\right).\left(1001.1002...1999\right)}}\)
=> \(C=\frac{2000.2001.2002....2999}{1.2.3...1000}.\frac{\left(1.2.3...1000\right).\left(1001.1002...1999\right)}{\left(1001.1002.1003....1999\right).\left(2000.2001.2002...2999\right)}=1\)
Đáp số: C=1
A = (1 + 1999/1)(1 + 1999/2)......(1 + 1999/1000)
B = ( 1 + 1000/1)(1 + 1000/2)......(1 + 1000/1999)
Tính A/B
\(A=\left(1+\dfrac{1999}{1}\right)\left(1+\dfrac{1999}{2}\right)...\left(1+\dfrac{1999}{1000}\right)\)
\(=\dfrac{2000}{1}.\dfrac{2001}{2}.\dfrac{2002}{3}...\dfrac{2999}{1000}\)\(=\dfrac{2000.2001.2002...2999}{1.2.3...1000}\)
\(B=\left(1+\dfrac{1000}{1}\right)\left(1+\dfrac{1000}{2}\right)...\left(1+\dfrac{1000}{1999}\right)\)
\(=\dfrac{1001}{1}.\dfrac{1002}{2}.\dfrac{1003}{3}...\dfrac{2999}{1999}\) \(=\dfrac{1001.1002.1003...2999}{1.2.3...1999}\)
\(\Rightarrow A:B=\left(\dfrac{2000.2001.2002...2999}{1.2.3...1000}\right):\left(\dfrac{1001.1002.1003...2999}{1.2.3...1999}\right)\)
\(=\dfrac{2000.2001.2002...2999}{1.2.3...1000}.\dfrac{1.2.3...1999}{1001.1002.1003...2999}\)
\(=\dfrac{2000.2001.2002...2999}{1.2.3...1000}.\dfrac{1.2.3...1000.\left(1001.1002...1999\right)}{1001.1002.1003....1999.\left(2000.2001.2002.2999\right)}\)\(=\dfrac{1.2.3...1000}{1.2.3...1000}=1\)
Vậy \(\dfrac{A}{B}=1\)
Tinh
(1 + 1999/1)(1 + 1999/2)......(1 + 1999/1000)
( 1 + 1000/1)(1 + 1000/2)......(1 + 1000/1999)
Tinh
(1 + 1999/1)(1 + 1999/2)......(1 + 1999/1000)
( 1 + 1000/1)(1 + 1000/2)......(1 + 1000/1999)
\(A=\frac{\left(1+\frac{1999}{1}\right)\left(1+\frac{1999}{2}\right)\left(1+\frac{1999}{3}\right)...\left(1+\frac{1999}{1000}\right)}{\left(1+\frac{1000}{1}\right)\left(1+\frac{1000}{2}\right)\left(1+\frac{1000}{3}\right)...\left(1+\frac{1000}{1999}\right)}\)
hỏi a = ?
HELP MEEE!!!
A = (1 + 1999/1)(1 + 1999/2)......(1 + 1999/1000)
B = ( 1 + 1000/1)(1 + 1000/2)......(1 + 1000/1999)
Tính A/B
Tính :
C= \(\frac{\left(1+\frac{1999}{1}\right)\left(1+\frac{1999}{2}\right)...\left(1+\frac{1999}{1000}\right)}{\left(1+\frac{1000}{2}\right)\left(1+\frac{1000}{2}\right)...\left(1+\frac{1000}{1999}\right)}\)
Tính \(A=\frac{\left(1+\frac{1999}{1}\right)\left(1+\frac{1999}{2}\right)....\left(1+\frac{1999}{1000}\right)}{\left(1+\frac{1000}{1}\right)\left(1+\frac{1000}{2}\right)....\left(1+\frac{1000}{1999}\right)}\)
\(A=\frac{\frac{2000\cdot2001\cdot2002\cdot...\cdot2999}{1\cdot2\cdot3\cdot...\cdot1000}}{\frac{1001\cdot1002\cdot1003\cdot...\cdot2999}{1\cdot2\cdot3\cdot...\cdot1999}}=\frac{2000\cdot2001\cdot2002\cdot...\cdot2999}{1\cdot2\cdot3\cdot...\cdot1000}\times\frac{1\cdot2\cdot3\cdot...\cdot1999}{1001\cdot1002\cdot1003\cdot...\cdot2999}\)
\(A=1\)