13. Sofia's car can travel 228 miles on 6 gallons of gas. a. Write an equation to represent the distance, $y$, in miles Sofia's car can travel on $x$ gallons of gas. b. Sofia's car used 7 gallons of gas during a trip. How far did Sofia drive?

Step 1 ：The problem is asking for two things. First, it wants an equation that represents the distance Sofia's car can travel on x gallons of gas. This is a simple ratio problem. We know that the car can travel 228 miles on 6 gallons of gas, so the ratio of miles to gallons is 228/6. This ratio will be the same for any number of gallons, so we can represent the distance y (in miles) that the car can travel on x gallons of gas as \(y = \frac{228}{6}x\).

Step 2 ：Second, the problem asks how far Sofia drove if her car used 7 gallons of gas. We can use the equation we just derived to find this. We just need to substitute 7 for x in the equation and solve for y.

Step 3 ：Calculate the miles per gallon ratio: \(\frac{228}{6} = 38.0\) miles per gallon.

Step 4 ：Substitute 7 for x in the equation \(y = 38x\) and solve for y: \(y = 38 \times 7 = 266\) miles.

Step 5 ：Final Answer: The equation to represent the distance, \(y\), in miles Sofia's car can travel on \(x\) gallons of gas is \(y = 38x\). If Sofia's car used 7 gallons of gas during a trip, she drove \(\boxed{266}\) miles.