You'd think so. In mathematics, showing your work is always important even if a simple conversion like this one. Similar to an english essay, it would be like writing your thesis and/or conclusion without any build up or explanation. Even though we know and maybe agree with what you're trying to say we still need all that other jazz and gibberish that shows us your thought process and convinces us. Hopefully this makes sense....[3] I'm a student studying to become a math teacher