Re: HSC 2013 3U Marathon Thread
$i)\ \ \ Given that $a=y+d $ use the binomial expansion of $(y+d)^{n},$ where $n$ is positive integer, to show that $a^{n}-y^{n-1}(y+nd)$ is divisible by $d^{2}
$ii)\ \ \ Hence show that if $a$ is the first term, $d$ the common difference, $L$ the $n$-th term of...