Can I get a second opinion or can someone help me with this question I think the answer is no what do yall think?

well, if we divide polynomial say P(x) by a another polynomial or expression say (x - a), if the quotient is 0, namely is the division yields a 0, then (x - a) is a factor of P(x).

the factor theorem which is a corollary of the remainder theorem states that, if (x - a) is indeed a factor of P(x), then

she did a check on f(-3), namely where x = -3, and got a remainder of 20, which is correct, however that simply means that (x + 3) is not a factor, if we want to check if (x - 3) is a factor or not, we ought to check for f(3).

when it comes to the (x-a) factors, you can think of them as, if the factor is say h (x + 4568) and we zero out the other side, then we end up with x + 4568 = 0 ==> x = -4568, and that's the value of "x" that we use in the remainder or factor theorem.

f(3) = 14, thus (x - 3) is not factor.

all it means is function 3