[tex]a_1=-10\\d=-2[/tex]
[tex]a_2=-10-2=-12\\a_3=-10-2-2=-14\\a_4=-10-2-2-2=-16\\a_5=-10-2-2-2-2=-18\\a_6=-10-2-2-2-2-2=-20\\a_7=-10-2-2-2-2-2-2=-22\\a_8=-10-2-2-2-2-2-2-2=-24\\a_9=-10-2-2-2-2-2-2-2-2=-26\\a_{10}=-10-2-2-2-2-2-2-2-2-2=-28[/tex]
[tex]a_n=-2n-8[/tex]