1、(3y+2x)(-----)=y^4-49x^2
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
已知x+y+2(-x-y+1)=3(1-y-x)-4(y+x-1),则x+y等于( )
设动点P与P'的坐标为(X,Y)(X',Y')它们满足X'=3X+2Y+1,Y'=X+4Y-3.
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y 2.(2(x-y)^3-8(x-y)^2(x+y)+6y(
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知x/2=y/3=z/4,求下列各式 (1)(x+y+z)/x (2)(x-y+2x/(x-y-2z)
已知x²+|y+x|=x-1/4,求(3x+y)²(2x-y)²-(4x²+y&
化简求值:【(x+Y)(X-Y)-(X-Y)的平方+2Y(2-Y)】除4Y,其中X=1 Y=2
(X-3Y)(X+3Y)-(X+2Y)(X-4Y)-(2X-Y)2的平方
设函数y=y(x)满足微分方程y″-3y′+2y=2e^x 且曲线y=y(x)在(0.1)处与已知曲线y=x^4-x+1