activity seven group key factor the following polynomial expression by grouping that they're with greatest common monomial factor show your complete solution with checking
1.ar+br+at+br
2.x(a-3)+y(3-a)
3.ab²-bc²+ab+c²
4.​6ab-b²+12bc
5.9m²+30mn+25n²+12m+20n-12​