Simplify: i) (a + b)(5a – 3b) + (a – 3b)(a – b) ii) (a – b) (a2 + b2 + ab) – (a + b) (a2 + b2 – ab) iii) (b2 – 49) (b + 7) + 343

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?