Answer:
Arnez is 4. Andell is 13. Marianne is 7.
Explanation:
Let x represent Arnez's age. If we write out an equation, we end up with this:
24 = (9 + x) + (x + 3) + x
24 = 9 + x + x + 3 + x
24 = (x + x + x) + (9 + 3)
24 = 3x + 12
24 - 12 = 3x + 12 - 12
12 / 3 = 3x / 3
4 = x