Odpowiedź :
[tex]f)~~(a+5)\cdot (b+1)=ab+a+5b+5\\\\g)~~(x+2)\cdot (y-3)=xy-3x+2y-6\\\\h)~~(m-3)\cdot (n+7)=mn+7m-3n-21\\\\i)~~(p-4)\cdot (q-5)=pq-5p-4q+20\\\\j)~~(a+2)\cdot (a-6)=a^{2} -6a+2a-12=a^{2} -4a-12[/tex]
[tex]f)~~(a+5)\cdot (b+1)=ab+a+5b+5\\\\g)~~(x+2)\cdot (y-3)=xy-3x+2y-6\\\\h)~~(m-3)\cdot (n+7)=mn+7m-3n-21\\\\i)~~(p-4)\cdot (q-5)=pq-5p-4q+20\\\\j)~~(a+2)\cdot (a-6)=a^{2} -6a+2a-12=a^{2} -4a-12[/tex]