Determine the type $($simple$,$ separable, linear, or none of the above$)$ of the given first$-$order differential equations.

Do not solve the equations. Note that some equations can be of several types simultaneously.

x$=$ tan$($x$/$t$)$a$)$ x$=$ tan$($x$)$b$)$ x$=$ tan$($t$)$c$)$

x$=$ x

tan$($t$)$

d$)$ x$=2$x $+1$

t $+2$

e$)$ x$=2$x $+$ t

x $+2$t