计算x²-y²-8x²+12y²
计算 [12(x+y)³(y-x)]³÷[4(x+y)²(x-y)]²
计算(x²/x+2y)-x+2y-2
计算:(x+y)²-4(x+y)(x-y)+4(x-y)²
计算:[(x+¼y)+(x-¼y)](2x²-1/8y²)
计算:x²-y²/x·-x²/(x-y)²;8y²y³·(-
计算:(xy-x²)×x-y/xy
计算6x³y^6÷(1/2)y³÷(-3x²y)-(12x^4y^6-8x²y^
利用公式计算(x²-y²)÷(x+y)
计算:(x-y)(x²+xy+y²)
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
计算:1、(xy分之x²-y²)×(x-y分之x)-(y分之x);
计算(x²+y²)²(x+y)²(x-y)²