Answer:
29
Explanation:
7 + 4 = 11 --> 4 = 2²
11 - 9 = 2 --> 9 = 3²
2 + 16 = 18 --> 16 = 4²
18 - 25 = -7 --> 25 = 5²
Notice that the pattern is adding and then subtracting the next square number up. Therefore, the next number in the sequence would be -7 + 36 = 29 since 6²=36.