Thu gon roi tinh gia tri tai x = 1, y = \(-\dfrac{1}{2}\)
M = ( 5x - 3y + 3xy + x2y2) - (\(\dfrac{1}{2}\)x + 2xy - y + 4x2y2)
Mn giup em voi a ! Em cam on nhieu lam ! Em dang can gap vo cung moi nguoi nhich chut thoi gian giup em a ! Mon nao em cx hoc dc het chi co Toan la bo tay thoi ! Mn giup e cam on truoc a
\(M=\left(5x-3y+3xy+x^2y^2\right)-\left(\dfrac{1}{2}x+2xy-y+4x^2y^2\right)\)
\(=5x-3y+3xy+x^2y^2-\dfrac{1}{2}x-2xy+y-4x^2y^2\)
\(=\left(5x-\dfrac{1}{2}x\right)+\left(y-3y\right)+\left(3xy-2xy\right)+\left(x^2y^2-4x^2y^2\right)\) \(=4,5x-2y+xy-3x^2y^2\)
Thay \(x=1;y=-\dfrac{1}{2}\) vào ta có:
\(4,5x-2y+xy-3x^2y^2\)
\(=4,5.1-2.\left(-\dfrac{1}{2}\right)+1.\left(-\dfrac{1}{2}\right)-3.1^2.\left(-\dfrac{1}{2}\right)^2\)
\(=4,5+1-\dfrac{1}{2}-\dfrac{3}{4}\) \(=\dfrac{17}{4}\)
