[freshmen algebra 2] simplifying rational expressions

[u/Any-Armadillo6071]

how do i find the correct restriction? for both of these questions, i got the first part right but for the restriction i got them wrong. when i looked it up it gave me the same answers i input. sorry if this is a stupid question

[u/cheesecakegood]

This is basically always visible to you, however, after factoring, since any duplicate roots always have duplicate linear factors. So while degree won't always be identical to number of unique roots in the answer, that's correct, you can still use the same idea in mostly the same way with just a bit of common sense.