Find the coefficient of `a^(2)b^(3)c^(4)d` in the expansion of `(a-b-c+d)^(10)`.

Explanation

To find the coefficient of \( a^2 b^3 c^4 d \) in the expansion of \( (a - b - c + d)^{10} \), we can use the multinomial theorem. The multinomial expansion of \( (x_1 + x_2 + x_3 + x_4)^n \) is given by:

\[ \sum \frac{n!}{k_1! k_2! k_3! k_4!} x_1^{k_1} x_2^{k_2} x_3^{k_3} x_4^{k_4} \]

where \( k_1 + k_2 + k_3 + k_4 = n \).

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