(x+1)/3=(y+2)/4 (x-3)/4- (y-3)/3=1/12
已知x+y+2(-x-y+1)=3(1-y-x)-4(y+x-1),则x+y等于( )
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
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.
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
已知x²+|y+x|=x-1/4,求(3x+y)²(2x-y)²-(4x²+y&
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)
数学二元一次方程 (x-y=2,2x+y=4 ) (x-y=1,3x-y=5) (x-y=8,3x+y=12 ) (a+
(1)y+3x+17=0 5y-2x+17=0 (2)x+y+z=12 x+2y+5z=22 x=4y (3)x+y+z
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
{x:y=3:4 (x-y):(y-1)=1:2
不解方程组x+4y=6 x-3y=1求代数式7y(x-3y)的平方-2(3y-x)的立方
已知x-y=1,求[(x+2y)2+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值.