1+1/3+1/6+...+1/x(x+1)=1/2003/2005
1/3+1/6+...+1/x(x+1)=2003/2005
1/2(1/3+1/6+..+1/x(x+1)=2003/4010
1/6+1/12+...+1/x(x+1)=2003/4010
1/2*3+1/3*4+...+1/x(x+1)=2003/4010
1/2-1/3+1/3-1/4+...+1/x-1/x+1=2003/4010
1/2-1/x+1=2003/4010
1/x+1=1/2005
x+1=2005
x=2004
Tính \(P=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2005}}{\frac{2004}{1}+\frac{2003}{2}+\frac{2002}{3}+...+\frac{1}{2014}}\)
giải phương trình \(\sqrt{2x+\frac{2013x-1}{\sqrt{2-x^2}}}-\sqrt[3]{2014-\frac{2013x-1}{\sqrt{2-x^2}}}=\sqrt{x+2003}-\sqrt[3]{x+1}\)
Cho A=\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\left(x+1\right)}=\frac{2015}{2017}\)
Tìm x
TOÁN 6 NHA
Tìm x thuộc N biết:
\(\frac{1}{2}+\frac{1}{28}+\frac{1}{36}+...+\frac{2}{x.\left(x+1\right)}=\frac{3}{10}\)
Tìm x:
\(x.\frac{1}{2}-x.\frac{2}{3}+x.\frac{3}{4}-x.\frac{5}{6}=\frac{5}{6}-\frac{3}{4}+\frac{2}{3}-\frac{1}{2}\)
help me pleas
câu 1 : Giải pt
\(\sqrt{x-1}+\sqrt{2x-1}=5\)
câu 2 : cho biểu thức
\(P=\frac{2\sqrt{x}}{\sqrt{x}+3}+\frac{\sqrt{x}+1}{\sqrt{x}-3}+\frac{3-11\sqrt{x}}{9-x}\)
a) rút gọn P
b) tìm x để P <1
câu 3 : cho
\(P=\left(1-\frac{2\sqrt{x}}{3\sqrt{x}+1}+\frac{\sqrt{x}+1}{9x-1}\right):\left(\frac{9\sqrt{x}+6}{3\sqrt{x}+1}\right)\)
a) rút gọn P
b) tìm x để P =\(\frac{6}{5}\)
c) cho m>1 . C/m P có 2 giá trị x thõa mãn P=m
tìm x
\(\frac{3}{2}\log_{\frac{1}{2}}\left(x+2\right)^2-3=\log_{\frac{1}{4}}\left(4-x\right)^3+\log_{\frac{1}{4}}\left(6+x\right)^3\)
Cho \(x=2005\). Tính giá trị của biểu thức \(x^{2005}2006x^{2004}+2006x^{2003}-2006x^{2002}+...-2006x^2+2006x-1\)