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audio read-through ‘Undoing’ a Sequence of Operations

Need some basic practice with the connection between expressions and sequences of operations first? Going from an Expression to a Sequence of Operations and Going from a Sequence of Operations to an Expression

In this exercise, you will practice ‘undoing’ operations.

The expression $\,2x + 1\,$ represents the sequence of operations: start with a number $\,x\,,$ multiply by $\,2\,,$ then add $\,1\,.$

To ‘undo’ these operations and get back to $\,x\,,$ we must apply the sequence: subtract $\,1\,,$ then divide by $\,2\,.$

Start with $\,x\,$ and follow the arrows in the diagram below. This shows you doing something, and then undoing it, to return to $\,x\,$!

$x$ $\overset{\quad\text{multiply by 2}\quad}{\rightarrow}$ $2x$ $\overset{\text{add 1}}{\rightarrow}$ $2x + 1$
        $\,\downarrow\,$
$x$ $\overset{\text{divide by 2}}{\leftarrow}$ $2x$ $\overset{\quad\text{subtract 1}\quad}{\leftarrow}$ $2x + 1$
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Remember some key ideas:

Master the ideas from this section by practicing below:

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When you're done practicing, move on to:

Solving for a Particular Variable
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Concept Practice

  1. Choose a specific problem type, or click ‘New problem’ for a random question.
  2. Think about your answer.
  3. Click ‘Check your answer’ to check!
PROBLEM TYPES:
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AVAILABLE
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Write the sequence of operations needed to get back to the number $\,x\,$:
To get a randomly-generated practice problem, click the ‘New problem’ button above.

Think about your answer, and then press ‘Enter’ or ‘Check your answer’.
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