1.rút gọn A=3\(\log_4\sqrt{a}\)- \(\log_{\dfrac{1}{2}}a^2\)+ 2\(\log_{\sqrt{2}}a\)
2.bt \(\log_23=a\). tính \(\log_{12}36\) theo a
Tính :
a) \(4^{\log_23}\)
b) \(27^{\log_92}\)
c) \(9^{\log_{\sqrt{3}}2}\)
d) \(4^{\log_827}\)
a) Cho \(a=\log_315;b=\log_310\). Hãy tính \(\log_{\sqrt{3}}50\) theo a, b ?
b) Cho \(a=\log_23;b=\log_35;c=\log_72\). Hãy tính \(\log_{140}63\) theo a, b, c ?
Tìm x:
\(\dfrac{4\sqrt{x}}{\sqrt{x}+1}=2^{1-3\sqrt{x}}\)
Tìm TXĐ:
a) y=\(\left(1-x\right)^{\dfrac{-1}{3}}\)
b) \(y=\sqrt{\log_{0,5}\dfrac{2x+1}{x+5}-2}\)
c) \(y=\log_{10}\sqrt{x^2-x-12}\)
d) \(y=\sqrt{\log_{10}x-1+\log_{10}x+1}\)
PT 2x-1 - \(2^{x^{2^{ }}-x}\)= (x-1)2 có bao nhiêu nghiệm?
Giải pt: 3.16x+2.81x=5.36x
Bài tập 3: Giải phương trình.
a, \(\log_52x-\log_5-x-2=0\)
b, \(9^x-3.3^x+2=0\)
Cho \(\left\{{}\begin{matrix}x;y;z>=0\\x+y+z=2\end{matrix}\right.\) CMR \(\dfrac{1}{x^2-xy+y^2}+\dfrac{1}{y^2-yz+z^2}+\dfrac{1}{z^2-xz+x^2}\ge3\)