计算:(1/2x+1/3y)^2
(2x+y)(x+3y-1)计算
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
1.计算(a^2+a+1)(a^2-a+1) 2.计算(x-y)(x+y)+(3x-2y)(2x+y)-x(6x-y)
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
数学用乘法公式计算(x+y+1)(x+y-1)(2x-y-3)²
(1)计算:a-(a^2)/(a+1)-1 (2)计算:3x/(x-4y)+(x+y)/(4y-x)-7y/(x-4y)
计算:(2/3x√9x+6x√y/x)+(y√x/y-√1/x)
计算:(-x-2y) * (3x-y)
已知x=2+根号3,y=2-根号3,计算代数式(x+y/x-y-x-y/x+y)乘以(1/x^2-1/y^2)
计算3xy[2xy-x(y-2)+x-1]
计算:3x-(4y-2x+1)
计算:1/2x-1/x+y×(x+y/2x-x-y)