PLEASEEE HELPPP MEEE WITH NUMBERS 9 AND 10

QUESTION: Find the measure of each numbered angle

What is the missing constant term in the perfect square that starts with x^2 -20x

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 of the following is true for the relation f(x)=2x^2+1