cho a,b,c,d>0, ctìm gtnn của (a+2a/3b)(1+2b/3c)(1+2c/3d)(1+2d/3a)
cho a,b,c,d >0.tim min
\(S=\)\(\left(1+\frac{2a}{3b}\right)\left(1+\frac{2b}{3c}\right)\left(1+\frac{2c}{3d}\right)\left(1+\frac{2d}{3a}\right)\)
Cho a, b, c, d > 0. Tìm Min :
\(S=\left(1+\frac{2a}{3b}\right)\left(1+\frac{2b}{3c}\right)\left(1+\frac{2c}{3d}\right)\left(1+\frac{2d}{3a}\right)\)
Cho a,b,c thỏa mãn (3a+3b+3c)3 = 24 + (3a+b-c)3 + (3b+c-a)3 + (3c+a-b)3 chứng minh (a+2b)(b+2c)(c+2a)=1
Chứng minh với a,b,c>0 thì\(a^3b+b^3c+c^3a\ge a^2b^2+b^2c^2+c^2a^2\)
Cho a,b,c,d >0. Chứng minh:
1. \(\frac{a}{2a+b+c}\)+\(\frac{b}{a+2b+c}\)+\(\frac{c}{a+b+2c}\)\(\ge\)\(\frac{3}{4}\)
2. \(\frac{a}{b+2c+3d}\)+\(\frac{b}{c+2d+3a}\)+\(\frac{c}{d+2a+3b}\)+\(\frac{d}{a+2b+3c}\)\(\ge\)\(\frac{2}{3}\)
Giúp mình với, mình đang cần gấp. Cảm ơn
cho a b c > 0
chứng minh rằng
a/(b+4c+2a) + b/(c+4a+2b) + c/(a+4b+2c) <= 1/2
(3a-b)/(a^2+ab) + (3b-c)/(b^2+cb) + (3c-a)/(ac^2+ac) <= a/bc +b/ac + c/ab
Cho a, b,c : abc = 1. Chứng minh:
\(\dfrac{a^2b^2}{2a^2+b^2+3a^2b^2}+\dfrac{b^2c^2}{2b^2+c^2+3b^2c^2}+\dfrac{c^2a^2}{2c^2+a^2+3a^2c^2}\le\dfrac{1}{2}\)
Cho a, b, c > 0 thỏa mãn : \(ab+bc+ca=3abc\)
Tìm GTLN : F = \(\dfrac{1}{a+2b+3c}+\dfrac{1}{2a+3b+c}+\dfrac{1}{3a+b+2c}\)