4^2-2 X 3 + 6 = ? SOLVE with PEMDAS

my son has had problems with algebra and tbh I don't know how to do it either i was hoping someone on here can help!

List the elements of the set in roster notation. (enter empty or ∅ for the empty set.) {x | x is a letter in the word hippopotamus}

Me. i need an answer asap. , you! select the correct answer from each drop-down menu.simplify the given polynomial and use it to complete the statement.the polynomial simplifies to an expression that is a blank with a blank degree of blank .

Need on this one asap im almost done with this subject