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Even though "x" is one of the least-used letters in the English alphabet, it appears throughout American culture—from Stan Lee's X-Men superheroes to "The X-Files" TV series. The letter x often ...

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Do you stare at a math word problem and feel completely stuck? You're not alone. These problems mix reading comprehension with complex math concepts, making them a common hurdle for students. The good ...

Add Yahoo as a preferred source to see more of our stories on Google. The use of the letter x as a mathematical unknown is a relatively modern convention. Algebra has been around for a lot longer.