Answer:
21 - 15 = 6 or 21 - 6 = 15
Explanation:
Pete is 15 years old. So, in order to find Victoria's age you would add the number of years Victoria is younger than Pete, which we know is 6. To find your answer you'd add 6 to 15 which equals 21. Now that you have your answer, you flip the equation 21 - 15 = 6 or 21 - 6 = 15
I hope this helps!