求墨迹部分是什么:(21x^4y³-墨迹+7x²y²)÷(-7x²y)=墨迹+5
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
求因式分解(x-y)²-2(x-y)³和(x+y)(x-y)-x(x-y)
已知x²-y²=10,求[(x+y)³-2y(x+y)²-4(x+y)]÷(x+
已知x,y为实数,且2(x+2y)=x²+y²+5求代数式3x-4y分之x²+y²
计算4(x+y)^5(x-y)^4÷[2(x+y)³*(y-x)²]
因式分解 -5x³y(x-y)³+20y【x²(y-x)】²
x(x-y)-y(y-x)+(x-y)²因式分解
【(X²+Y²)-(X-Y)²+2Y(X-Y)】/4Y=1,求4X/4X²-Y&
{(x-y)²+(x+y)(x-y)}÷2x
x²+y²-4x+6y+13=0,求(3x+y)²-3(3x+y)(x+y)-(x-3y)
化简[21x^5y^7-28x^7y^4+7y(2x³y²)²]÷(-7x^5y^4)
不解方程组{2x+Y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值.