a/c +b/c+b/a+c/a+c/b+a/b>=6 ( ap dung cosi)
a/c +b/c+b/a+c/a+c/b+a/b>=6 ( ap dung cosi)
bài 1 choa,b,c>0 CMR: \(\frac{a+3c}{a+b}+\frac{a+3b}{a+c}+\frac{a+3c}{b+c}>=5\)
\(Cho\)\(a;b;c>0\)\(.\)\(CMR\)\(:\)
\(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}+\frac{9\sqrt[3]{abc}}{a+b+c}\ge6\)
\(\frac{a+b}{c}+\frac{b+c}{a}+\frac{c+a}{b}\ge6,\left(a,b,c>0\right)\)
Cho a;b;c>0 và a+b+c=3. Chứng minh
\(\frac{3+a^2}{b+c}+\frac{3+b^2}{c+a}+\frac{3+c^2}{a+b}\ge6\)
Cho a,b,c >0 CMR : \(\frac{c\left(ab+1\right)^2}{b^2\left(bc+1\right)}+\frac{a\left(bc+1\right)^2}{c^2\left(ac+1\right)}+\frac{b\left(ac+1\right)^2}{a^2\left(ab+1\right)}\ge6\)
Cho a,b,c dương. CMR:
a) \(a+\frac{a}{1+ab}+\frac{4}{a+2c}\ge\frac{8a}{1+ab+ac}\)
b) \(\frac{4a}{b}+\frac{3b}{a}+\frac{b}{a+b}\ge6\)
chứng minh các bất phương trình
\(A=\left(a+b\right)\left(\frac{1}{a}+\frac{1}{b}\right)\ge4\)
\(B=\left(\frac{a+b}{c}\right)+\frac{b+c}{a}+\frac{c+a}{b}\ge6\left(a,b,c>0\right)\)
Với a,b,c>0.CMR:\(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}=\frac{a}{c}+\frac{b}{a}+\frac{c}{b}\)
Choa a+b+c=0
tính \(M=\frac{1}{a^2+b^2-c^2}+\frac{1}{a^2+c^2-b^2}+\frac{1}{b^2+c^2-a^2}\)
trình bày cách làm nữa nha