The first three terms of the arithmetic sequence are 290, 283, 276.
The first three terms of the arithmetic sequence can be found using the formula for the nth term of an arithmetic sequence:
a_n = a_1 + (n - 1) * d
Given that a_25 = 122 and d = -7, we can substitute these values into the formula to find the first three terms:
a_1 = a_25 - (25 - 1) * d = 122 - 24 * (-7) = 122 + 168 = 290
The first three terms of the sequence are: 290, 283, 276.