Question

Write down and simplify:
The 10th term of ${(1-2x)}^{12}$

Answer 1

We know that the $r^{th}$ term in expansion of $(a+x{)}^n$ is given by ${}^n{C}_{r-1}{a}^{n+1-r}{x}^{r-1}$

$\therefore$ the tenth term in expansion of $(1-2x{)}^{12}$ is ${}^{12}{C}_3(-2x{)}^9=-112640x^9$