(1 point) Find the solution to the following lhcc recurrence:
an = -2an-1 + 15an-2 for n ≥ 2 with initial conditions ao = 3, a₁ = 3. The solution is of the form:
an = a₁(r1)n + a₂(r₂)n
for suitable constants a1, a2, r1, r2 with r1 ≤ r2. Find these constants.