cho a,b,c>0. CMR:\(\frac{\left(a+b\right)^2}{a^2+b^2+2c^2}+\frac{\left(b+c\right)^2}{b^2+c^2+2a^2}+\frac{\left(c+a\right)^2}{c^2+a^2+2b^2}\le3\)
Cho a,b,c > 0:abc=1
Cmr: \(\dfrac{1}{a^2+2b^2+3}+\dfrac{1}{b^2+2c^2+3}+\dfrac{1}{c^2+2a^2+3}\le\dfrac{1}{2}\)
cho a,b,c>0. Cmr:
\(\sqrt{\frac{a^3}{a^3+\left(b+c\right)^3}}+\sqrt{\frac{b^3}{b^3+\left(a+c\right)^3}}+\sqrt{\frac{c^3}{c^3+\left(a+b\right)^3}}\ge1\)
giải các PT sau :
a) \(\left|2x+3\right|-\left|x\right|+\left|x-1\right|=2x+4\)
b) \(\sqrt{x}-\dfrac{4}{\sqrt{x+2}}+\sqrt{x+2}=0\)
c) \(\sqrt{x+\sqrt{2x-1}}+\sqrt{x-\sqrt{2x-1}}=\sqrt{2}\)
d) \(x+\sqrt{x+\dfrac{1}{2}+\sqrt{x+\dfrac{1}{4}}}=4\)
e) \(\sqrt{4x+3}+\sqrt{2x+1}=6x+\sqrt{8x^2+10x+3}-16\)
f)\(\sqrt[3]{x-2}+\sqrt{x+1}=3\)
GIÚP MÌNH VỚI MÌNH ĐANG CẦN GẤP
Cho p,q > 0 : \(\dfrac{1}{p}+\dfrac{1}{q}=1;u,v\ge0\)
CHứng minh rằng \(u.v\le\dfrac{u^p}{p}+\dfrac{v^q}{q}\)
Cho f,g : \(\left[a,b\right]\rightarrow R\) Liên tục và p,q ở câu (a) ta luôn có :
\(\int\limits^b_a\left|f\left(x\right).g\left(x\right)\right|dx\le\left(\int\limits^b_a\left|f\left(x\right)\right|^pdx\right)^{\dfrac{1}{p}}\left(\int\limits^b_a\left|g\left(x\right)\right|^qdx\right)^{\dfrac{1}{q}}\)
giải hệ phương trình
a,\(\left\{{}\begin{matrix}\dfrac{2}{x}+\dfrac{3}{y}=5\\\dfrac{1}{x}-\dfrac{4}{y}=-3\end{matrix}\right.\)
b,\(\left\{{}\begin{matrix}\dfrac{12}{x-3}-\dfrac{5}{y+2}=63\\\dfrac{8}{x-3}+\dfrac{15}{y+2}=-13\end{matrix}\right.\)
c,\(\left\{{}\begin{matrix}\dfrac{4}{x+2}-\dfrac{1}{x-2y}=1\\\dfrac{20}{x+2y}+\dfrac{3}{x-2y}=1\end{matrix}\right.\)
d,\(\left\{{}\begin{matrix}\left|x-1\right|+\left|y-2\right|=2\\\left|x-1\right|+y=3\end{matrix}\right.\)
a) \(\dfrac{5x-2}{2-2x}\)+\(\dfrac{2x-1}{2}\)=1-\(\dfrac{x^2+x-3}{1-x}\)
b)\(\dfrac{1-6x}{x-2}+\dfrac{9x+4}{x+2}\)=\(\dfrac{x\left(3x-1\right)+1}{\left(x-2\right).\left(x-2\right)}\)
c)1+\(\dfrac{x}{3-x}\)=\(\dfrac{3x}{\left(x+2\right).\left(x-3\right)}+\dfrac{2}{x+2}\)
cho a,b,c>0. Cmr:
\(\frac{a}{a+\sqrt{\left(a+b\right)\left(a+c\right)}}+\frac{b}{b+\sqrt{\left(b+a\right)\left(b+c\right)}}+\frac{c}{c+\sqrt{\left(c+a\right)\left(c+b\right)}}\le1\)
Giải các phương trình sau:
a, \(\dfrac{x+1}{x^2+2x+4}-\dfrac{x-2}{x^2-2x+4}=\dfrac{6}{x\left(x^4+4x+16\right)}\)
b, \(\left(12x+7\right)^2\left(3x+2\right)\left(2x+1\right)=3\)
c, \(x^4+2008x^2+2007x=2008\)
d, \(2x\left(8x-1\right)^2\left(4x-1\right)=9\)
e, \(x^4+2010x^2+2009x=2010\)
g, \(\left(x+y+z\right)^3-x^3-y^3-z^3=0\)