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What is the coefficient of the x⁴-term in the binomial expansion of (x³)¹²?

a. (12/7​)⋅(3)⁷
b. (12​/8)
c. (12​/4)⋅(3)
d. (12/8​)⋅(3)⁸

User FKaria
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1 Answer

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Final answer:

To find the coefficient of the x⁴-term in the binomial expansion of (x³)¹², you can use the binomial theorem. Option c is correct.

Step-by-step explanation:

To find the coefficient of the x⁴-term in the binomial expansion of (x³)¹², we can use the binomial theorem. The binomial theorem states that for a binomial expression raised to a power, the coefficient of a specific term can be found using the formula: C(n, r) * a^(n-r) * b^r, where n is the power, r is the term number, a is the coefficient of the first term, and b is the coefficient of the second term.

In this case, our binomial expression is (x³)¹², so a = x³, b = 1, n = 12, and we want to find the coefficient of the x⁴-term, which corresponds to r = 8.

The question asks for the coefficient of the x⁴-term in the binomial expansion of (x³)¹². When expanding the expression, the power on the x gets multiplied by the power outside the parentheses due to the rules of exponents, as in (xa)b = xa·b. Since we are looking for the x⁴-term, and the given expression is (x³)¹², which simplifies to x¹⁶, there is no x⁴-term in this expansion because x⁴ is not a factor of x¹⁶.

Using the formula, we can calculate: C(12, 8) * (x³)^(12-8) * 1^8 = C(12, 8) * x⁴ * 1 = C(12, 8) * x⁴

The coefficient of the x⁴-term is therefore C(12, 8).

User Alana
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