Final answer:
The values of a are not required for the solution x≤7 to represent the interval (-∞,7]; if an exclusive interval is needed, the condition would be x<7 to represent the interval (-∞,7).
Step-by-step explanation:
To find the values of a such that the solution x≤7 represents the interval (-∞,7), we want to establish a relationship for a that satisfies this condition for x. However, based on the information provided, there appears to be a misunderstanding in the question since the condition given initially as x≤5 does not align with the query for the interval (-∞,7).
For a proper alignment with standard interval notation, if we want the solution to be in the form x≤7, we are actually saying that x can take any value less than or equal to 7. This suggests that there is no further condition on a since the inequality directly describes the interval (-∞,7] (inclusive of 7). If the condition needs to be exclusive, meaning not including 7, it would be conveyed as x<7, corresponding to the interval (-∞,7) (exclusive of 7).