Answer: the correct equation :

The value of x= $60
Explanation:
Let the total cost of the food be x .
Given that , Tram left a tip of $9, which was
of the total cost of the food.
According to this statement , we have

Multiply 20 on both sides , we get


Divide both sides by 3 , we get

i.e. the total cost of the food = $60
Thus , the correct equation :

The value of x= $60, where x is the total cost of the food.