General solution of differential equations

$\frac{d y}{d x}+y=1(y \neq 1)$ is

The degree of the differential equation $\left[1+\left(\frac{d y}{d x}\right)^2\right]^2=\frac{d^2 y}{d x^2}$ is

The integrating factor of the differential equation

$x \cdot \frac{d y}{d x}+2 y=x^2$ is $(x \neq 0)$