Question

Please help me !!!

Answer 1

$9)~6mn-9m-4n+6=3m(2n-3)-2(2n-3)=(3m-2)(2n-3)\\\\ 10)~a^3+a^2b+ab+b^2=a^2(a+b)+b(a+b)=(a^2+b)(a+b)\\\\ 11)~4r^2s-8rs-3r+6=4rs(r-2)-3(r-2)=(4rs-3)(r-2)\\\\ 12)~x^2y^2-3x^2+2y^2-6=x^2(y^2-3)+2(y^2-3)=\\\\=(x^2+2)(y^2-3)$