Please help me answer this question and if you can please give me the step by step solution. Thank You!

The sum of two numbers is 12 and their difference is 18 what are the two numbers

How can you find the mean absolute deviation (mad) for this set of data?

Jessica is organizing a guided tour of the rain forest. the average profit per person that the touring company makes is given by the rational expression 18x+35/x, where x is the number of people going on the tour. what does the numerator of this rational expression represents?