1. The problem describes a number line with points A, 4, and B in that order. There is a green arrow labeled "+5" pointing from A to 4 and a purple arrow labeled "+8" pointing from 4 to B. 2. The green arrow "+5" means that the distance from A to 4 is 5 units. Since 4 is to the right of A, we write: $$4 - A = 5$$ 3. Solve for A: $$A = 4 - 5 = -1$$ 4. The purple arrow "+8" means the distance from 4 to B is 8 units. Since B is to the right of 4: $$B - 4 = 8$$ 5. Solve for B: $$B = 4 + 8 = 12$$ 6. Therefore, the values replacing A and B on the number line are: $$A = -1$$ $$B = 12$$