Which situation CANNOT be represented by this equation? 3x – 5 = 25 Clay has 25 marbles to trade for some of Mark's baseball cards. If Clay makes the trade today, Mark will give him a discount of 5 marbles. If each card is worth 3 marbles, how many baseball cards, x, will Clay get? Clay has 25 marbles to trade for some of Mark's baseball cards. If Clay makes the trade today, Mark will give him a discount of 3 marbles. If each card is worth 5 marbles, how many baseball cards, x, will Clay get? Clay has 25 marbles to trade for some of Mark's baseball cards. If Clay makes a trade today, Mark will give him a discount of 5 marbles. If Clay receives 3 baseball cards, how many marbles, x, was each card worth?