Marcus earns money from feeding cats and answering emails. he earns $7 a week for each cat he feeds and $0.20 for each email he answers. marcus answered 140 emails and earned $49 last week. part a: create an equation that will determine the number of cats he fed. (3 points) part b: solve this equation justifying each step with an algebraic property of equality. (6 points) part c: how many cats did marcus feed last week?