Solve the system by graphing. x + 2y = -7 --x + y = 1​

Ineeeeed this is due tomorrow and i dont know the answer can you find all the exponents

Find the cosine function that is represented in the graph.

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.