大师作文网y=(x+4)(x+9)/x (x>0)
y=(x+4)(x+9)/x (x>0)
计算分段函数：y=6x*x+9x-7 (x大于等于0时)；y=3x*x+4x-5 (x小于0时)
已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值
y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1
若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7
y=x^x（x>0)求导
x-y+5x-4x= ?
y=x+4/x (x
｛4/(x+y)+6/(x-y)=3 ｛9/(x-y)-1/(x+y)=1
已知4x=9y求(1)x+y/y (2)y-x/2x
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知4x+y-4x-6y+10=0,求(三分之二x√9x+y√y分之x)-x√x分之1-5x√x分之y)的值