Precalculus Examples

$\sum_{k = 2}^{6} {(- 1)}^{k + 1} (2^{k})$

Step 1

Expand the series for each value of $k$ .

${(- 1)}^{2 + 1} \cdot 2^{2} + {(- 1)}^{3 + 1} \cdot 2^{3} + {(- 1)}^{4 + 1} \cdot 2^{4} + \dots + {(- 1)}^{6 + 1} \cdot 2^{6}$

Step 2

Simplify the expanded form.

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