(1)1200+4Y=500X
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
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+y=4,求(x+1/x)(y+1/y)的min
(1)1200+4Y=500X
已知x+y+2(-x-y+1)=3(1-y-x)-4(y+x-1),则x+y等于( )
化简求值(x+5y)(x+4y)-(x-y)(x+y),其中x=一又2/5,y=-1/7
利用关系式判断,y和x成什么比例 8x=y( ) x/4=y( ) y/8=5/x( ) 1/x=y( )
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.
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
实数X.Y满足X*X+Y*Y-2X-2Y+1=0,则(Y-4)/(X-2)的取值范围是?
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
{3(x+y)+3(y+x)=1,3(x+y)+4(y-x)=-1