Factorization by grouping, then use common factor method

Got it !

$4(y-5) + 25a-5ay =$	$ (y-5)(4-5a)$
$(x-5)^2-2x+10 =$	$(x-5)(x-7) $
$3x^2+6x-x-2 =$	$(3x+1)(x+2) $
$2x^2-3x-4x+6 =$	$(2x-3)(x-2) $
$2x^2+7x+3 =$	$(2x+1)(x+3) $ in fact $7x=6x+x $ !
$2x^3+10x^2+3x+15$	$(x+5)(2x^2+3) $