



 
Hi Johan, I think you are expected to use algebra to solve this problem. If so here are two approaches.
I however wouldn't use algebra to solve this. I instead would ask "Find two numbers whose difference is zero and whose sum is 120." That is I want the two numbers to be the same and their sum is 120. What are they? Increase one of the numbers by 1 and decrease the other by 1. Their sum is still 120 but their difference is 2. Increase the large by 1 and decrease the smaller by 1. Their sum is still 120. What is their difference? How many times do you have to do this until their difference is 16? Penny  


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