68-89

I’m missing the context. Do you want solutions for exam problems numbered 68–89 from a specific book or course? If you can share the exact problem statements (or a photo/text of problems 68–89), I’ll work through them step by step. If you can’t share them, tell me: - the subject (e.g., Calculus, Linear Algebra, Physics, CS) - the chapter or topic range those problems come from I can then: - provide a general approach or template for that type of problem - generate practice problems of similar style - or wait for you to paste the exact 68–89 problems and I’ll solve them with explanations.