Ta có: \(A=x^2-4y^2+x-2y\)
\(=\left(x-2y\right)\left(x+2y\right)+\left(x-2y\right)\)
\(=\left(x-2y\right)\left(x+2y+1\right)\)
tim gia tri nho nhat cua bieu thuc A = x2 -2xy + 4y2 -2x -10y +3
cho x,y khac nhau biet x2-y=y2-x. tinh gia tri cua bieu thuc A=x2+2xy+y2-3x-3y
cho x-y=3.tinh gia tri bieu thuc A=x(2x+4y-4)+2y(y-5x+2)+2xy
Tinh gia tri cua bieu thuc A=x-2009/2009x+y
Biet x^2-2y^2=xy( voi 2009x+y khac 0 )
cho x+y =1 . tinh gia tri cua bieu thuc A=x^3+y^3+3xy
chox-y=1. tinh gia tri cua bieu thuc B=x^3-y^3-3xy
cho x+y=1 . tinh gia tri cua bieu thuc C=x^3+y^3+3xy(x^2+y^2)+6x^2*y^2(x+y)
Cho x2-2y2=xy. Tinh gia tri cua bieu thuc M=\(\frac{x-y}{x+y}\)
Cho:x ^2-2xy+2y^2-2x+6y+5=0.Tinh gia tri bieu thuc:3x^2y-1/4xy
cho x>y>0 va 2x2+2y2=5xy
tinh gia tri bieu thuc E=x+y/x-y
cho\(x^2-2xy+2y^2-2x+6y+5=0\)tinh gia tri cua bieu thuc \(\frac{3x^2y-1}{4xy}\)
