1/(6x-4y)-(1)/(6x+4y)-(3x)/(4y^2-9x^2)
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
{4/(x+y)+6/(x-y)=3 {9/(x-y)-1/(x+y)=1
化简求值:(7x-2y)(3x-2y-1)-(4x+3y)(9x+6y),其中x=2,y=-1
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
(x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3)
已知4x=9y求(1)x+y/y (2)y-x/2x
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
计算(4x^2-2x^3+6x)/(-2x)-(x-1)^2y^2-4/y^2-y-6)+(y+2/y-3)/(y+1/
化简求值:(x+y)-(2x+1/2y)-(3x+1/6y)-(4x+1/12y)-(5x+1/20y)-.(10x+1
9y=3x-(x-1),4(x+y)-(2x+4)=8y