chung mnh rang:x^2+xy+y^2-3x-3y+3 lon hon hoac bang 0
cho cac so thuc x,y,z thoa man 0<a<hoac=x,y,z < hoac=b . tim gia tri lon nhat cua bieu thuc
T= I ab-xy I / (x+y)x + I bc-yz I / (y+z)x + Ica-zxI / (z+x)y
ai lam duoc cau nay minh cong nhan la gioi
cho 2 so duong x,y thoa man x+y=1 CMR 1/x+y + 2/x^2+y^2 > hoac = 8
1 . tong binh phuong tat ca cac nghiem cua phuong trinh : x4(x-1)+(x-1)x3=0
2.neu da thuc 2m3-m+n co 2 nhan tu la : x+2 va x-1 thi gia tri cua 2m+3n la
3.tong x; y thoa man (x-2015)2+(y-2014)4>hoac bang 0 la ?
cho 2 so x,y thoa man 2(x^2+y^2)=2015. Gia tri lon nhat cua x+y la:...
cho x+y =2. chung minh rang x^2015+y^2015 ba hon hoac bang x^2016+y^2016
cho x;y;z #0 thoa man 1/xy + 1/yz + 1/zx =0
tinh N = x2/yz + y2/xz + z2/xy
cho x,y thuoc R khac 0 thoa man 2x^2 + y^2/4 +1/x^2 = 4. tim gtnn gtln cua A= 2008+xy
ho ba so x y z thoa man x + y +z =3. gia tri lon nhat cua bieu thuc p= xy +yz+ xz