1.(x^2+4)^2-16x^2=?2.-3x^3+6x^y-3xy^2=?
x^+2xy+y^+4=16 x^-2xy+y^=16 求(3xy+6y^)+|x^-(2xy+2y^-3x^)|的值
(-3x^y+2xy)-( )=4x^+xy
[3xy(1-x)-6xy(x-1/2)]*2x*(-xy)平方,x=-1 y=2 ; 3xy平方(-1/3x平方y+4
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
x-y=1,xy=2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
-3(2x-xy)-4(-6+xy+x.其中x=1,y=-1
已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
-3xy(x^2-2x-1)+(2x-3y)(3x-4y)=?
已知x+xy=-2,xy-y=-6求代数式2x{-4y-3[(x+xy)²+x]-½[(y-xy
x-2y=5 xy=-2.x²+4y²=?(x+2y)²=?x²-3x-6x+6