I may make exceptions with advanced notice. On joint work, indicate who did the final writing. If you work regularly with someone, take turns doing the final writing. If you receive significant assistance on a problem from someone not in the class, student or faculty, you must acknowledge that assistance. This will not count against you.
Problems are to be written neatly and clearly.
Mathematics isn't just computations and answers, it's explanations of why something is true. Some credit will be given for the quality and clarity of the write-up. This is measured by how well another linear algebra student could read and learn from what you have written. Don't turn in your scratch work. After you have solved a problem, write it up neatly.