The equatio `(x ^(2 ))/( 2 -r) + (y ^(2))/(r -5) +1=0` represents an ellipse, if

The equation (x^2)/(2 - r) + (y^2)/(r - 5) + 1 = 0 represent an ellipse iff

If equation (x^(2))/(2-r) + (y^(2))/(r-5) + 1 = 0 represents ellipse then …….

The equation (x^(2))/(2-lamda)-(y^(2))/(lamda-5)-1=0 , represent and ellipse, if

The equation (x^(2))/(2-lambda)+(y^(2))/(lambda-5)-1=0 represents an ellipse if

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

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

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