Marc and his brother ty start saving money at the same time. marc has $145 and will add $10 to his savings every week. ty has $20 and will add $15 to his savings every week. a. write an equation to represent the number of weeks marc and ty will have the same amount saved equation: b. after how many weeks will marc and ty have the same amount? show your work. weeks: c. what is that amount? show your work. amount: