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Question
Write the sum of the coefficients in the expansion of \[\left( 1 - 3x + x^2 \right)^{111}\]
Solution
\[\text{ To find the sum of coefficients, we plug 1 for each variable } \]
\[\text{ then, we get the sum of coefficients of the given expression . } \]
\[ \therefore \text{ Sum of coefficient } = \left( 1 - 3x + x^2 \right)^{111} \]
\[ = \left( 1 - 3 \times 1 + 1^2 \right)^{111} \]
\[ = \left( 1 - 3 + 1 \right)^{111} \]
\[ = \left( 1 - 3 + 1 \right)^{111} \]
\[ = \left( - 1 \right)^{111} \]
\[ = - 1\]
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