Jake made a total of 7 copies at a copy shop, with some being black-and-white copies and some being color copies. Black-and-white copies cost 8 cents, and color copies cost 15 cents. If Jake spent a total of 70 cents on copies, which
system of equations can be used to determine the number of black-and-white copies and the number of color copies he
made? Assume b is the number of black-and-white copies and c is the number of color copies.

b+c= 7
8b+ 15C = 70

b+c=7
15b+8C = 70

b+c= 70
8b+ 15 = 7

+C = 70
15b+8C = 7