=2999

X + 50 - 78 = 759

X + 50        = 759 + 78

X + 50        = 837

X               = 837 - 50

X               = 787

Q = \(Q=\dfrac{x^3}{y+z}+\dfrac{y^3}{x+z}+\dfrac{z^3}{x+y}\)

Tìm Qmin biết x+y+z \(\ge\)6 , x,y,z> 0

Cho a,b,c >0 thõa mãn a+b+c = 3

\(CMR:\dfrac{a^3}{b\left(2c+a\right)}+\dfrac{b^3}{c\left(2a+b\right)}+\dfrac{c^3}{a\left(2b+c\right)}\ge1\)

Cho a,b,c > 0 thõa mãn a+b+c=3

\(CMR:\dfrac{a^3}{\left(a+b\right)\left(a+c\right)}+\dfrac{b^3}{\left(a+b\right)\left(b+c\right)}+\dfrac{c^3}{\left(c+a\right)\left(c+b\right)}\ge\dfrac{3}{4}\)

cho a,b,c >0 thõa mãn abc = 1

\(CMR:\dfrac{a^3}{\left(1+b\right)\left(1+c\right)}+\dfrac{b^3}{\left(1+c\right)\left(1+a\right)}+\dfrac{c^3}{\left(1+a\right)\left(a+b\right)}\ge\dfrac{3}{4}\)

CHo a+b+c=1 (a,b,c>0) CMR:

S=\(\dfrac{bc}{\sqrt{a+bc}}+\dfrac{ac}{\sqrt{b+ac}}+\dfrac{ab}{\sqrt{c+ab}}\le\dfrac{1}{2}\)