Passive Voice to active voice conversion doubt
Solution 1:
As noted in the comments, the difficulty with transforming passive voice to active voice is the need for a subject. In your example, who is reserving history education for those with money? Is it the rich themselves? Is it those in authority? Is it us in some sense? Once you're able/willing to identify a subject, converting to active voice becomes pretty straightforward.
This is why passive voice is used: To avoid assigning responsibility of the action to a specific agent. This might be because there's no one responsible agent, or the responsible agent is irrelevant, or you don't want to cast blame.