Question

9x^2-12xy+3y^2=
6x^2-x-2=
2x^2-7x+5=

Answer 1

$9x^2-12xy+3y^2= 3(3x^2-4xy+y^2) = 3(x-y)(3x-y);\\ 6x^2-x-2= (2x+1)(3x-2); \\ 2x^2-7x+5= (2x-5)(x-1) .$