3z+18+x+72+3y=180 solve for x, y, and z. will give brainliest PLEASE SOLVE QUICK

Math i have no idea how to do a and b

Which equation represents a direct linear variationa. y=x2b. y=2/5xc. y=1/xd. y=x+3

Plz hurry finals a paper cup in the shape of an inverted cone is 8 inches tall and has a radius of 1.5 inches. how much water can the cup hold? use 3.14 for pi. round the answer to the nearest tenth. a) 12.6 cubic in. b) 18.8 cubic in. c) 37.7 cubic in. d) 56.5 cubic in.