NDA2010MathematicsBinomial TheoremActual
What is the coefficient of x¹⁷ in the expansion of (3 x- x^3 6 )^9 ?
Options
- A189/8
- B567/2
- C21/16
- DNone of the above
Correct answer
A. 189/8
Step-by-step solution
Coefficient of x¹⁷ in (3 x- x^3 6 )^9 aligned & =9 C₄(3 x)⁹⁻⁴ (- x^3 6 )^4 & =9 C₄ 3^5 (- 1 6 )^4 & = 19 4 5 3^5 6^4 = 189 8 aligned