bonnie goes out to eat and buys a meal that costs $12.50 that includes tax of $0.75. she only wants to leave a tip based on the cost of the food. what equation could help bonnie calculate the tip?

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.