The order is the highest numbered derivative in the equation with no negative or fractional power of the dependent variable and its derivatives, while the degree is the highest power to which a derivative is raised.

Here in this question the dependent variable is x, and thus the order of the equation is 2, and the degree of the equation is 1.

In a differential equation, when the dependent variable and their derivatives are only multiplied by constants or independent variable, then the equation is linear.

Here dependent variable x and its derivatives are multiplied with a constant or independent variable only so this equation is linear differential equation.