Find the coefficient a of the term in the expansion of the binomial. Binomial Term $( x - 3 y ) ^ { 9 }$ $a x ^ { 5 } y ^ { 4 }$
A)a = 13
B)a = 10206
C)a = 45
D)a = -19683
E)a = 3024

Question

Quizplus · Accepted Answer

The coefficient of the term $a x ^ { 5 } y ^ { 4 }$ in the expansion of the binomial $( x - 3 y ) ^ { 9 }$ is given by the binomial coefficient:$$a = \binom{9}{5} = \frac{9!}{5!4!} = \frac{9 \times 8 \times 7 \times 6}{4 \times 3 \times 2 \times 1} = 10206$$

Find the Coefficient a of the Term in the Expansion (x−3y)9( x - 3 y ) ^ { 9 }(x−3y)9

Find the Coefficient a of the Term in the Expansion $( x - 3 y ) ^ { 9 }$