化简求值:[x(x2y2-xy)-y(x2-x3y)]÷3x2y,其中x=3,y=-1.
化简求值:[x(x2y2-xy)-y(x2-x3y)]÷3x2y,其中x=3,y=-1.
计算:[x(x2y2-xy)-y(x2+x3y)]÷3x2y.
计算:[x(x2y2-xy)-y(x2-x3y)]÷3x2y.
化简求值:2(x2y+xy)-3(x2y-xy)-4x2y,其中x=-1,y=1.
化简并求值:(2x2y-2xy2)-[(-3x2y2+3x2y)+(3x2y2-3xy2)],其中x=−12,y=2
化简求值(2X2-2y2)-3(X2y2+X2)+3(X2y2+y2),其中X=-1,y=2
(2x2y-2xy2)-[(-3x2y2+3x2y)+(3x2y2-3xy2)],其中x=-1,y=2.
先化简后求值:4x2y-[6xy-3(4xy-2)-x2y]+1,其中x=2,y=-12
先化简,后求值.[2x(x2y-xy2)+xy(xy-x2)]÷x2y,其中x=2013,y=2012.
若x+y=-1,则x4+5x3y+x2y+8x2y2+xy2+5xy3+y4的值等于( )
有这样一道题,计算(2x4-4x3y-x2y2)-2(x4-2x3y-y3)+x2y2的值,其中x=0.25,y=-1;
先化简,再求值(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.