Binomial Expansion Term Identification

00:00 4 marks

Find the term in $x^3$ in the expansion of $(2x – \frac{1}{x})^7$.

Hint Hint

Hint

Write the general term as $T_r = \binom{7}{r}(2x)^{7-r}(-\frac{1}{x})^r$ and simplify it to $\binom{7}{r}2^{7-r}(-1)^r x^{7-2r}$. Then, set the exponent $7-2r=3$ to solve for $r$.

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Answer Answer

Complete Answer

The term in $x^3$ is $672x^3$.

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Common Errors Common Errors

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