Answer:

Step-by-step explanation:

Following PEMDAS, we multiply from left to right first.


Then, we add/subtract from left to right.


Can you add the picture with it cuz i think you forgot
21 is a composite number and the closest number to 20
20 total balls:
5 are black
17 NOT yellow
12 NOT green
20-17 = 3
20-12 = 8
5 Black + 3 yellow + 8 green = 16 balls
20 total balls - 16 balls = 4 blue balls
Ewa has 4 blue balls.