Question

The greatest term (numerically) in the expansion of (2 + 3x)⁹, when x = 3/2 is –

• A. $\frac{5 \times 3^{11}}{2}$
• B. $\frac{5 \times 3^{13}}{2}$
• C. $\frac{7 \times 3^{13}}{2}$
• D. None of these

Answer 1

Answer: (C)

$\frac{7 \times 3^{13}}{2}$

Answer 2

r = $\frac{(n + 1)|a|}{|x| + |a|}$ = $\frac{(10)|3x|}{|2| + |3x|}$ = $\frac{10 \times 9/2}{13/2}$ = $\frac{90}{13}$

Q 6 < r < 7

\ T₇ = 2⁹$\left( 1 + \frac{3x}{2} \right)^{9}$

= $\frac{7 \times 3^{13}}{2}$