N = 3/5.7 + 3/7.9 + 3/9.11 + ... + 3/197.199
(nhớ có cả lời giải nhé )
N = \(\frac{3}{5.7}+\frac{3}{7.9}+\frac{3}{9.11}+...+\frac{3}{197.199}\)
(nhớ có cả lời giải nhé )
\(N=\frac{3}{2}\cdot\left(\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}+...+\frac{1}{197}-\frac{1}{199}\right)\)
\(N=\frac{3}{2}\cdot\left(\frac{1}{5}-\frac{1}{199}\right)\)
\(N=\frac{3}{2}\cdot\frac{194}{995}\)
\(N=\frac{291}{995}\)
N = \(\frac{3}{5.7}+\frac{3}{7.9}+\frac{3}{9.11}+...+\frac{3}{197.199}\)
(nhớ có lời giải nhé)
N=\(3.\left(\frac{1}{5.7}+\frac{1}{7.9}+...+\frac{1}{197.199}\right)\)
N=\(\frac{3}{2}.\left(\frac{2}{5.7}+\frac{2}{7.9}+...+\frac{2}{197.199}\right)\)
N=\(\frac{3}{2}.\left(\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+...+\frac{1}{197}-\frac{1}{199}\right)\)
N=\(\frac{3}{2}.\left(\frac{1}{5}-\frac{1}{999}\right)\)
N=\(\frac{3}{2}.\frac{194}{995}\)
N=\(\frac{291}{995}\)
= 3/5-3/7+3/7-3/9+3/9-3/11+......+3/197-3/199
= 3/5-3/199
= 582/995
N = \(\frac{3}{5.7}+\frac{3}{7.9}+\frac{3}{9.11}+...+\frac{3}{197.199}\)
(nhớ có lời giải nhé)
N=3/2(1/5-1/7+1/7-1/9+1/9-1/11+...+1/197-1/199)
N=3/2(1/5-1/199)=3/2.194/995=291/995
\(\frac{2}{3}N=\frac{1}{5.7}+\frac{1}{7.9}+\frac{1}{9.11}+...+\frac{1}{197.199}\)
\(=\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}+...+\frac{1}{197}-\frac{1}{199}\)
\(=\frac{1}{5}-\frac{1}{199}\)
\(=\frac{194}{995}\)
=> \(N=\frac{194}{995}:\frac{2}{3}=\frac{291}{995}\)
=> 2N = 2.3/5.7 + 2.3/7.9 + 2.3/9.11 + ... + 2.3/197.199
=> 2N = 3. (1/5 - 1/7 + 1/7 - 1/9 + 1/9 - 1/11 + ... + 1/197 - 1/199
=> 2N = 3. (1/5 - 1/199) = 3. 194/995 = 582/995
=> N = 582/995 : 2 = 291/995
Tinh bang mt do nha.
N = 3/5.7 + 3/7.9 + 3/9.11 +.....+3/197.199
N=3/2.(1/5.7+1/7.9+1/9.11+....+1/197.199)
N=3/2.(1/5-1/7+1/7-1/9+1/9-1/11+....+1/197-1/199)
N=3/2.(1/5-1/199)
N=3/2.194/995
N=291/995
Có N = 3 . (1/5 . 7 + 1/7 . 9 + .... + 1/197 . 199)
2N = 3 . (2/5 . 7 + 2/7 . 9 + ... + 2/197 . 199)
2N = 3 . (1/5 - 1/7 + 1/7 - 1/9 + ... + 1/197 - 1/199)
2N = 3 . (1/5 - 1/199)
N = \(\frac{3.\left(\frac{1}{5}-\frac{1}{199}\right)}{2}\)
N = (3 . 194/995) : 2
Bạn tự tính nốt nhé chúc bạn học tốt
Tính:
a) M=2/3.5+2/5.7+2/7.9+...+2/97.99
b) N=3/5.7+3/7.9+3/9.11+...+3/197.199
a.
\(M=1.\left[\frac{1}{3}-\frac{1}{5}+.....\frac{1}{97}-\frac{1}{99}\right]\)
\(M=\frac{1}{3}-\frac{1}{99}=\frac{32}{99}\)
b.
\(N=\frac{3}{2}.\left[\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+...+\frac{1}{197}-\frac{1}{199}\right]\)
\(N=\frac{3}{2}.\left[\frac{1}{5}-\frac{1}{199}\right]=\frac{291}{995}\)
mk đầu tiên nha bạn
tính
\(N=\frac{3}{5.7}+\frac{3}{7.9}+\frac{3}{9.11}+...+\frac{3}{197.199}\)
giải giúp mih nha
BÀi này dễ thôi bạn ạ
N=3(1/5.7+1/7.9+.........+1/197.199)
N=3/2( 1/5-1/7+1/7-1/9+1/9-..........+1/197-1/199)
N=3/2(1/5-1/199)
N=3/2.194/995
N=291/995
k đúng cho mình nhé
N=3.1/2.(1/5-1/7+1/7-1/9+1/9-1/11+...+1/197-1/199)
N=3.1/2.(1/5-1/99)
N=3.1/2.94/495
N=3.47/495
N=47/165
N=3/5.7+3/7.9+........+3/197.199
=>N=3/2(2/5.7+2/7.9+.....+2/197.199)
=>N=3/2(1/5-1/7+1/7-1/9+........+1/197-1/199)
=>N=3/2(1/5-1/199)
=>N=3/2x194/995=291/995
a) M = 2/3.5 + 2/5.7 + 2/7.9 + ... + 2/97.99
b) N = 3/5.7 + 3/7.9 + 3/9.11 + ... + 3/197.199
c) P = 1/1.2 + 2/2.4 + 3/4.7 + ... + 10/46.56
Tính
N = 3/5.7 + 3/79 + 3/9.11 + ... + 3/197.199
P = 1/1.2 + 2/2.4 + 3/4.7 + ... + 10/46.56
Mong các bạn giải theo các bước giùm mình nhé
P = 1 - 1/2 + 1/2 - 1/4 + 1/4 - 1/7 + ... + 1/46 - 1/56
P = 1 - 1/56
P = 55/56
Tính
N = 3/5.7 + 3/79 + 3/9.11 + ... + 3/197.199
P = 1/1.2 + 2/2.4 + 3/4.7 + ... + 10/46.56
Mong các bạn giải theo các bước giùm mình nhé