Answer: He can use 3 x 5 = 15 and 15 + 3.
Step-by-step explanation:
Since a small car is $3, and the large car is 5x the price of the small car, he can use the equation 3 x 5 = 15, because the small car is $3, and the large car is 5x the price. You can use 15 + 3 = 18, because the small car is $3, so you also have to add that.
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