Is linear algebra and differential equations harder than Calc 3?

It is difficult to answer this question definitively, as the difficulty of a course can vary from person to person. Generally speaking, linear algebra and differential equations are more abstract and require more mathematical maturity than Calculus 3. However, some people may find Calculus 3 more difficult due to its more rigorous approach to problem solving. Ultimately, the difficulty of each course will depend on the individual's background and level of understanding.