Are 9(4-x) and 36-9x equivalent expressions explain how you know

Josephine has a great garden with and area of 2x2 + x - 6 square feet

Scarlet bought three pairs of sunglasses and two shirts for $81 and paula bought one pair of sunglasses and five shirts for $105 what is the cost of one pair of sunglasses and one shirt?

You are at a restaurant and owe $56.20 for your meal. you want to leave an 18% tip. approximately how much is your tip?