Answer:**What is asked in the problem?**The problem asks how much of Ron's savings will be left after buying the stereo and speakers.**What are the given?**- Ron's total savings: ₱12,720- Cost of the stereo: ₱9,899.99- Cost of the speakers: ₱915.50**What operation is to be used?**Subtraction is used to find out how much money remains after the purchases.**What is the number sentence?**₱12,720 - (₱9,899.99 + ₱915.50)**Solve the problem:**1. Add the costs of the stereo and speakers: ₱9,899.99 + ₱915.50 = ₱10,815.492. Subtract this total from Ron's savings: ₱12,720 - ₱10,815.49 = ₱1,904.51**What is the answer?**Ron will have approximately ₱1,904.51 left after the purchase.