Choosing a number from 1 to 20 and a color from 7 colors

please answer

Question and answers are in the attached picture. you so much in advance.

Find the solution(s) to the system of equations. select all that apply y=x^2-1 y=2x-2

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.