Mrs. traivs rode her bike 17.8 miles the first week, 21.5 miles the second week, and 13.4 the third week. the rest of her mileage was in the final week of the month. her total mileage for the month was 62.9 miles. [part a] use the numbers and symbols from the box to write an expression to represent the distance mrs. travis rode in the final week of the month. o ) [options: x, +, -, 62.9, 21.5, 17.8, 13.4] [side note: o can be x, +, or -.] [part b] use the expression to find the number of miles mrs. travis rode her bike in the final week of the month.