C. 7
Explanation:Given:
AB = 5
BC = 3x + 7
AC = 5x - 2
Since the points A, B, and C are collinear:
AB + BC = AC
Substitute the given values into the equation above:
5 + 3x + 7 = 5x - 2
Collect like terms
5x - 3x = 5 + 7 + 2
2x = 14
Divide both sides by 2
2x/2 = 14/2
x = 7
