1. She can travel 18 miles. Subtract 35 - 2 (initial fee) to have 33. divide 33 by 1.75 to get 18.85. To check how much her total would be, use inverse operations. 18.85 * 1.75 = 32.9875. 32.9875 + 2 = 34.9875. It is barely under $35 but still in her budget.
2. 20m * $1.75 = $35. $70 - $35 = $35. Yes, she can cover the fare. Samantha has more than needed. She can afford the taxi fare and still have money left for future use.