I am struggling to figure out how to solve the Mult-produce monopoly problem

2. Multi-product monopoly An online news site earns revenue by selling subscriptiorls at price ps aud ads at price pa. For simplicity, assume the site zero marginal cost. Consumer demand for subscriptions is given by Demand from advertisers for ad-space depends on the number of subscribers through qa qs(l pa). 2.1. Compute the prices of subscription and ad-space that maximize the total profits from selling subscription and ad-space. 2.2. Suppuse the site has a new CEO who is only choxsing subscription price to maximize subscription profit; the CEO does not care about ad-space profit... Compute the optimal subscription price. why the sulcription price is higher than in 2.1.