What is the surface area of this wedge

Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy?

Consider the system: y = 3x + 5 y = ax + b what values for a and b make the system inconsistent? what values for a and b make the system consistent and dependent? explain

Which of the following are accepted without proof in a logical system? check all that apply.