(1+2x)/(1-2x)^2 এর বিস্তৃতিতে x¹⁰ এর সহগ কোনটি? 

$\begin{array}{l}\text { } \frac{1+2 x}{(1-2 x)^{2}} \\ =(1+2 x)(1-2 x)^{-2} \\ =(1+2 x)\left\{1+2.2 x+3 .(2 x)^{2}+\ldots . .\right. \\ \left.+10(2 x)^{9}+11(2 x)^{10}+\ldots\right\} \\ \therefore \mathrm{x}^{10} \text { এর সरগ }=\left(11 \times 2^{10}\right)+\left(2 \times 10 \times 2^{9}\right) \\ =21504 \\\end{array}$