What is the answer to -12= -2x-4x

Need this asap if anyone can i would be very grateful. if you could show workings that would really

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.

What ratio is proportional to 18/21