Answer :
Each number is the previous number subtracted by four
7 - 4 = 3
3 - 4 = -1
-1 - 4 = -5
-5 - 4 = -9
Answer: -9 - 4 = -13
7 - 4 = 3
3 - 4 = -1
-1 - 4 = -5
-5 - 4 = -9
Answer: -9 - 4 = -13