Which formula should be used?

Draw a tape diagram to represent each situation.for some of the situations,you need to decide what to represent with a variable andre bakes 9 pans of brownies.he donates 7 pans to the school bake sale and keeps the rest to divide equally among his class of 30 students

What is the total surface area of this square pyramid?

Find the value of x. give reasons to justify your solutions! c ∈ ae