The order of the differential equation whose solution is $y = a\cos x + b\sin x + c{e^{ - x}}$ is

The differential equation whose solution is $Ax^2 + By^2 = 1$,where $A$ and $B$ are arbitrary constants,is of:

The order and degree of the differential equation $\sqrt[4]{\left(\frac{d^3 y}{d x^3}\right)^5} = \sqrt[3]{\left(\frac{d^2 y}{d x^2}\right)^4}$ are . . . . . . and . . . . . . respectively.

The order and degree of the differential equation $\frac{d^{2} y}{d x^{2}}=\sqrt[3]{1-\left(\frac{d y}{d x}\right)^{4}}$ are respectively

Assertion $(A)$: The order of the differential equation of a family of circles with a constant radius is $2$.
Reason $(R)$: An algebraic equation having two arbitrary constants is the general solution of a second-order differential equation.

The order of the differential equation $y \left( \frac{dy}{dx} \right) = \frac{x}{\frac{dy}{dx} + \left( \frac{dy}{dx} \right)^3}$ is