" The equation "(x^(2))/(10-a)+(y^(2))/(4-a)=1" represents an ellipse if "

The equation (x^(2))/(10-k)+(y^(2))/(k-4)=1 represents an ellipse if

The equation (x^(2))/(1-r)+(y^(2))/(r-3)+1=0 represents an ellipse if :

The equation (x^(2))/(10-lamda)+(y^(2))/(4-lamda)=1 represents an ellipse if

Equation (x^(2))/(r-2) + (y^(2))/(5-r) = 1 represents an ellipse if

If the equation (x^(2))/(16 -K) + (y^(2))/(5-K) = 1 represents an ellipse , then

If the equation (x^(2))/(9-k)+(y^(2))/(5-k)=1 represents an ellipse then

If the equation (x^(2))/(9-c)+(y^(2))/(5-c)=1 represents an ellipse, then the foci are

The equation x^2/(12-a)+y^2/(4-a)=1 represents an ellipse, if :

The equation x^(2)/(r-2)+y^(2)/(5-r)= 1 represents an ellipse if

The equation (x^(2))/(1-r)-(y^(2))/(1+r)=1,r>1 represents (a)an ellipse (b) a hyperbola (c)a circle (d) none of these