Answer :
These 4 consecutive multiples of 3 are of the form
3N, 3 (N + 1), 3 (N + 2), 3 (N + 3)
The given constraint is captured in the equation
5 (3N + 3 (N + 3)) = 13 (3 (N + 2)) - 6
Solve for N :
5 (3N + 3N + 9) = 13 (3N + 6) - 6
5 (6N + 9) = 13 (3N + 6) - 6
30N + 45 = 39N + 78 - 6
30N + 45 = 39N + 72
30N - 39N = 72 - 45
-9N = 27
N = 27/(-9)
N = -3
Then the 5 consecutive multiples of 3 are
-9, -6, -3, 0