Why aren't we using the multiplication sign? | Introduction to algebra | Algebra I | Khan Academy

Khan Academy5 minutes read

Variables in mathematics are commonly represented by symbols like "x," but other letters and Greek symbols can also be used. Different notations, such as "2 dot x" or writing the number and variable next to each other in parentheses, can help avoid confusion between variables and multiplication symbols. When evaluating expressions with variables and numbers, remember that the multiplication operation takes precedence over addition or subtraction for the correct answer.

Insights

  • Different symbols can represent variables in mathematics, with "x" being the most popular choice, alongside other letters and Greek symbols.
  • To prevent confusion between variables and multiplication symbols, alternate notations like "2 dot x" or placing the number and variable together in parentheses can be utilized.

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Recent questions

  • What is the most common variable symbol in mathematics?

    "x"

  • How can confusion between variables and multiplication symbols be avoided?

    Use different notations like "2 dot x" or parentheses.

  • What takes precedence in evaluating expressions with variables?

    Multiplication operation over addition or subtraction.

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Summary

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Understanding Variables and Mathematical Notations

  • Variables in mathematics can be represented by various symbols, with "x" being the most commonly used one, although other letters and Greek symbols are also utilized.
  • To avoid confusion between the variable "x" and the multiplication symbol, different notations can be used such as "2 dot x" or writing the number and variable next to each other in parentheses.
  • When evaluating expressions with variables, such as "10 minus three y" when "y" is 2, the multiplication operation takes precedence over addition or subtraction, leading to the correct answer of 4.
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