cho x,y,z la cac so thuc duong thoa man x+y+z=1 tim min A=x^3/(x^2+xy+y^2)+y^3/(y^2+yz+z^2)+z^3/(z^2+zx+x^2)
a) tim GTNN, GTLN cua A = \(\sqrt{\left(x-1\right)}\)+\(\sqrt{\left(5-x\right)}\)
b) cho cac so duong x,y thoa man x+y>=3
CM: x+y+1/2x+2/y>=9/2
cho cac so nguyen duong x,y thoa man
x-y=x3-y3
cmr x2+y2<1
may ban gium mk nhanh nha cam on
Cho cac so duong x,y thoa man \(x^2+y^3\ge y^3+y^4\)
Cmr \(x^3+y^3\le x^2+y^2\le x+y\le2\)
cho cac so thuc duong x,y thoa man x+y<=3.Tim GTNN cua 1/5xy + 5/x+2y+5
Cho cac so duong x,y thoa man dieu kien \(x^2+y^3\ge x^3+y^4\)
Chung minh \(x^3+y^3\le x^2+y^2\le x+y\le2\)
a)Tim cap (x,y) nguyen duong thoa man xy=3(y-x)
b)cho 2 so x,y >0 thoa man x+y = 1
Tim GTNN cua M=(x^2+1/y^2)(y^2+1/x^2)
a)Tim tat ca cac so nguyen duong x, y , z thoa man: \(\frac{x+y\sqrt{2013}}{y+z\sqrt{2013}}\)la so huu ti, dong thoi x2 + y2+ z2 la so nguyen to.
b) Tim so tu nhien x, y thoa man: x(1+x+x2) = y(y-1).
Cho \(B=\frac{x^3}{1+Y}+\frac{Y^3}{1+x}\) trong do x, y la cac so duong thoa man dieu kien xy = 1. CMR \(B\ge1\)
