Ron bought some toy cars at a garage sale. He gave 5 cars to his sister and had 2 cars left. Which equation, when solved, will tell how many cars Ron bought at the garage sale?
Alright, so let's call the number of cars he buys "x" So we know he gives 5 to his sister, so we have to subtract 5 from the total amount, then we know there is 2 left.