bdt

cho a,b,c là các số tm đk a\geq 1;b\geq 1;c\geq 1 cm\frac{1}{2a-1}+\frac{1}{2b-1}+\frac{1}{2c-1}+\frac{4ab}{1+ab}+\frac{4bc}{1+bc}+\frac{4ac}{1+ac} \geq 9 thanks m.n ak

Bài 1: Cho a,b,c>=0; a+b+c=1.CMR \sqrt{a+\frac{(b-c)^{2}}{4}}\leq a+\frac{b+c}{2} Bài 2: Cho x,y>=0 ; x^2+2y^2=1.CMR \sqrt{1+2x}+\sqrt{1+2y}\geq 1+\sqrt{1+\sqrt{2}} Bài 3: Cho a,b>=0.CMR \left ( a^{2}+b+\frac{3}{4} \right )\left ( b^{2}+a+\frac{3}{4} \right )\geq (2a+\frac{1}{2})(2b+\frac{1}{2})...

Cho a,b,c >0 ; a^2+b^2+c^2=1. CMR \sum ab/(\sqrt{c+ab})\leq \frac{1}{2}