I need help with linear functions can anybody help me?

Which of the choices shown could be used to prove that aacp=abcp ?

Fatima plans to spend at least $15 and at most $20 dollars on sketch pads and pencils. if she buys 2 sketchpads, how many pemcils can she buy while staying in her price range? fatima can buy between and pencils. ? (type whole numbers. use ascending? order.)

Which of the following constants can be added to x2 - 3x to form a perfect square trinomial?