1/1.3+1/3.5+............+1/x.(x+2) = 50/102
2/1.3+2/3.3+...........+2/x.(x+2) =50/51
1-1/x+2=50/51
x+1/x+2=50/51
(x+1).51=(x+2).50
51x+51=50x+100
51x-50x=100-51
x=49
vay x=49
Tìm x, biết \(\left(1+\frac{1}{1.3}\right).\left(1+\frac{1}{2.4}\right).\left(1+\frac{1}{3.5}\right)....\left(1+\frac{1}{x\left(x+2\right)}\right)=\frac{4016}{2007}\)
Tìm x
\(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{x.\left(x+2\right)}=\frac{20}{41}\)
Tìm x
\(\left|x+\frac{1}{1.3}\right|+\left|x+\frac{1}{3.5}\right|+...+\left|x+\frac{1}{97.99}\right|\)
\(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{x.\left(x+2\right)}=\frac{5}{11}\)
Tìm x
Tìm x, biết:
\(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{x.\left(x+2\right)}=\frac{20}{41}\)
Tìm x,y
a, \(\left|3x-1\right|+\left(y-2\right)^2=0\)
b \(\frac{1}{5.6}+\frac{1}{6.7}+....+\frac{1}{x.\left(x+1\right)}=\frac{19}{100}\)
c. \(\frac{1}{1.3}+\frac{1}{3.5}+....+\frac{1}{x.\left(x+2\right)}=\frac{49}{99}\)
d. \(\left(2x+1\right).\left(y-2\right)=6\)
e \(^{x^2-3xy+3y-x=1}\)
Tìm x, biết:
a. \(\left(\frac{2}{1.3}+\frac{2}{3.5}+....+\frac{2}{97.99}\right)-x=\frac{-100}{99}\)
b. \(2+\frac{2}{3}+\frac{2}{6}+\frac{2}{7}+.......+\frac{2}{x.\left(x+1\right)}=1\frac{1989}{1991}\)
\(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+.....+\frac{1}{\left(2n+1\right).\left(2n+3\right)}\)
Tìm X :
\(\frac{2}{1.3}+\frac{2}{3.5}+...+\frac{2}{X.\left(X+2\right)}
