(-3xy)(5x²y)+6x平方(2/7xy²-2y²)
(-3xy)(5x²y)+6x平方(2/7xy²-2y²)
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
(3X平方-5Y)+[-3XY-2(X平方-XY)+Y平方]
化简(3X²-XY+Y²)-5(X²-XY+2Y²)
(2X平方y+3xy平方)-(6x平方-3XY平方)(计算)
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
计算:(-7x²y)(2x²y-3xy³+xy)
xy(xy+1)+(xy+3)-2(x+y+2分之一)-(x+y-1)的平方
已知x/2=y/3(xy≠0),求x²-2xy-3y²/x²-6xy-7y²的值
(-x²+2xy-y的平方)-2(xy—3x²)+3(2y的平方-xy) 计算.
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
已知;x+y=4,x-y的绝对值=6,求xy(y的平方+y)-y的平方(xy+2x)-3xy