2x-3y-8=0,5y-7x-5=0
y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组,
{2x+y/3-2y=0 2(2x+y)-5=7y
微分方程(1)(y'')^2+5y'-y+x=0;(2)y''+5y'+4y^2-8x=0;(3)(3x+2y)dx+(
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值
x1:4x-3y=8;y=7-5x;2:2x-7y=8,3x-8y-10=0;3:4x-y=-1;4:5x-10y+15
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
若|3x-y-7|+(5x+2y-8)2=0,则x-y=______.
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
一、3x-5y=53x-4y=23二、2x-7y=83x-8y-10=0三、x/3+x/4=23x-4y=-7
若|y+5|+(5x+1)^2=0,求-3(2x-y)-{7x-[6x+2y-(10x-8y)]-x-2(3x-4y)}