Final answer:
To be able to ride in a car together, you can weigh at most 177 pounds.
Step-by-step explanation:
To find out how much you can weigh to be able to ride in a car together, you need to subtract your friend's weight from the maximum weight allowed per car. Since your friend weighs 86 pounds and the maximum weight allowed is 263 pounds, the inequality would be x + 86 ≤ 263, where x represents your weight. To solve for x, subtract 86 from both sides of the inequality: x ≤ 263 - 86, which simplifies to x ≤ 177. Therefore, you can weigh at most 177 pounds to be able to ride in a car together.