tìm số tự nhiên x biết : 1/1.3+1/3.5+1/5.7+....+1/(2x-1)(2x+1)=49/99
Tìm x biết :\(\dfrac{1}{1.3}+\dfrac{1}{3.5}+\dfrac{1}{5.7}+...+\dfrac{1}{\left(2x-1\right)\left(2x+1\right)}=\dfrac{49}{99}\)
1/1.3+1/3.5+1/5.7+....+1/(2x-1)(2x+1)=49/99
\(\dfrac{1}{1.3}+\dfrac{1}{3.5}+\dfrac{1}{5.7}+......+\dfrac{1}{\left(2x-1\right)\left(2x+1\right)}=\dfrac{49}{99}\)
Tìm x:
|x+1/1.3|+|x+1/3.5|+|x+1/5.7|+...+|x+1/97.99|
Tìm x, biết:
1/1.3+1/2.3+...+1/5.7+1/(2x-1).(2x+1)=49/99
\(D=\frac{1}{1.3}-\frac{1}{2.4}+\frac{1}{3.5}-\frac{1}{4.6}+\frac{1}{5.7}-\frac{1}{6.8}+\frac{1}{7.9}-\frac{1}{8.10}\)
Help me!~~~~~~~~~~~~~
Tìm x: [12/11-(1/2+1/44].(x-0,2)=1/1.3+1/3.5+1/5.7+1/7.9+1/9.11
Tìm số tự nhiên x thỏa mãn 1/1.3 + 1/3.5 + 1/5.7 + ...+ 1/x(x + 2) = 8/17