9 is what percent of 30

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Which answer goes into the box? (90° clockwise rotation, 90° counter clockwise rotation, translation, or glide reflection)

Which expression is the factorization of x^2+10+21