Explanation
Correct answer: 15,-5.
By the definition of absolute value, if , then or . Adding to both sides of the first equation yields . Adding to both sides of the second equation yields . Thus, the given equation has two possible solutions, and . Note that 15 and -5 are examples of ways to enter a correct answer.
Desmos solution:
Enter in Desmos:
Reviewed and rewritten by CookSAT