$1) 2x²+5x-3$
$=2x²+6x-x-3$
$=2x(x+3)-(x+3)$
$=(2x-1)(x+3)$
$2)$ $x^{4}$+$2009x²+2008x+2009$
=$x^{4}$-$x+2009x²+2009x+2009$
=$x(x³-1)+2009(x²+x+1)$
=$x(x-1)(x²+x+1)+2009(x²+x+1)$
= $(x²+x+1)[x(x-1)+2009]$
= $(x²+x+1)(x²-x+2009)$
$Chúc$ $bạn$ $học$ $tốt!$