Ответ:\(7ab+7ac=7a(b+c)\);\(5mn-5m=5m(n-1)\);\(4ax+8a=4a(x+2)\);\(6ab-3bc=3b(2a-c)\);\(-15ax-20ay=-5a(3x+4y)\);\(-2mn-4n=-2n(m+2)\).