Final answer:
To form an equation representing this situation, we need to determine the initial amount of money Ed had before spending £7.50 on a shirt. Let x be the amount of money he started with. The equation x - 7.50 = (1/3)x represents this situation.
Step-by-step explanation:
To form an equation representing this situation, we need to determine the initial amount of money Ed had before spending £7.50 on a shirt. Let x be the amount of money he started with. According to the problem, Ed now has one-third of what he started with after spending £7.50. Therefore, we can write the equation x - 7.50 = (1/3)x to represent this situation.