计算(3x+2y-1)(3x-2y+1)
计算:1/(2x) - 1/(x+y)((x+y)/(2x) - x - y)
计算(1)x/x+y-x/x-y (2)a+2+4/a+2 (3)x^2-y^2/xy÷(x+y)
(x+y)^2-(3x-2y)^2计算
(2x+y)(x+3y-1)计算
计算:(3x-y)2-(2x+y)2+5x(y-x)
计算:(3x-4y)-[-(2y+x)+(x-3y)]-6x
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
计算:(2/3x根号下9x+6x根号下y/x)+(y根号下x/y-x的平方根号下1/x)=
计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8
计算①(1+x+2y)^2 ②(2x-7y)(3x+4y-1)
计算:(-x-2y) * (3x-y)
计算:3x+2y/4=2x+y/5=x-y+1/6.(要求有过程)