(3x+4y)²-(3x-4y)²=
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
化简 3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)²
因式分解:(x-y)(3x-7y)²-4(x-y)(x+y)²
4x+5y=105,2x+3y=178,x,y等于
(3x-y)²-2x(4x-5y)-(x+2y)²
求值(x-2y)²-4(x-2y)+2(x-2y)²-3(x-2y),其中x=-1,y=2分之1
(x+y)和(x-y)各看成一个整体,合并同类项2(x+y)-3(x-y)²+3(x+y)+4(x-y)
已知X²+3XY-4Y²=0(Y≠0)求X-Y/X+Y
已知x²+|y+x|=x-1/4,求(3x+y)²(2x-y)²-(4x²+y&
{3(x+y)+3(y+x)=1,3(x+y)+4(y-x)=-1
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1