What is the value of the following expression: $1 - 4 + 7 - 10 + 13 - \cdots - 46 + 49 - 52 + 55$ ?
Question:
What is the value of the following expression: $1 - 4 + 7 - 10 + 13 - \cdots - 46 + 49 - 52 + 55$ ?
Answer:
Let's think step by step.

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What is the value of the following expression: $1 - 4 + 7 - 10 + 13 - \cdots - 46 + 49 - 52 + 55$ ?
train