How to evaluate expressions with two variables | 6th grade | Khan Academy

Khan Academy2 minutes read

Simply substitute the given values for each variable into the expression to find the result, such as a plus b equals 9 when a is 7 and b is 2, and x times y minus y plus 3x equals 13 when x is 3 and y is 2.

Insights

  • Substituting specific values for variables in expressions simplifies the process of evaluating complex mathematical equations, leading to a clear and definitive result without ambiguity.
  • Understanding how to substitute values for variables in mathematical expressions enables precise calculations and aids in solving equations efficiently, demonstrating the practical application of algebraic principles in real-world scenarios.

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Recent questions

  • How do you evaluate expressions with multiple variables?

    To evaluate expressions with multiple variables, substitute the given values for each variable into the expression. For instance, if a equals 7 and b equals 2, the expression a plus b equals 9. Similarly, the expression x times y minus y plus 3x simplifies to 13 when x is 3 and y is 2.

  • What is the process for finding the result of an expression?

    The process for finding the result of an expression involves substituting the given values for each variable into the expression. By replacing the variables with their respective values, you can simplify the expression and calculate the final result.

  • Can you provide an example of evaluating expressions with variables?

    An example of evaluating expressions with variables is when a equals 7 and b equals 2, the expression a plus b equals 9. Similarly, the expression x times y minus y plus 3x simplifies to 13 when x is 3 and y is 2.

  • How do you simplify expressions with multiple variables?

    To simplify expressions with multiple variables, substitute the given values for each variable into the expression. By replacing the variables with their respective values, you can simplify the expression and calculate the final result.

  • What is the key step in evaluating expressions with variables?

    The key step in evaluating expressions with variables is to substitute the given values for each variable into the expression. By replacing the variables with their respective values, you can simplify the expression and find the result.

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Summary

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Substitute values to simplify expressions with variables.

  • When evaluating expressions with multiple variables, simply substitute the given values for each variable into the expression to find the result. For example, when a equals 7 and b equals 2, the expression a plus b equals 9. Another example is the expression x times y minus y plus 3x, which simplifies to 13 when x is 3 and y is 2.
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