Been stuck on this for a bit

Which of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?

Marco states that 7.696696669…… is a rational number because it is a repeating decimal. is he correct? justify your answer.

The graph represents this system of equations: 2x + y = 3 2x - 5y = 15 what is the solution to the system of equations represented by the graph? (0, -3) (1,1) (1.5,0) (2.5, -2)