clara states that r^2 +5r+3r is an equivalent expression to 9r. why is clara statement incorrect choose all that apply

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

The pyramid shown has a square base that is 24 centimeters on each side. the slant height is 16 centimeters. what is the lateral surface area?

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.