Answer:
141
Step-by-step explanation:
The interior angles of a polygon with n sides is 180(n - 2) and the polygon has 7 sides, so the sum of its interior angles is 180(7 - 2) = 180(5) = 900.
125 + (x + 7) + 107 + (x - 15) + x + 131 + 122 = 900
Combining like terms,
3x + 477 = 900
3x = 423
x = 141
