Задача №11912

$8\cos 15^{\circ }\cos 75^{\circ }$$8\cos 15^{\circ }\cos 75^{\circ }$$$8\cos 15^{\circ }\cos 75^{\circ }$$

$-6\cos 15^{\circ }\cos 105^{\circ }$$-6\cos 15^{\circ }\cos 105^{\circ }$$$-6\cos 15^{\circ }\cos 105^{\circ }$$

$12\sin 15^{\circ }\sin 75^{\circ }$$12\sin 15^{\circ }\sin 75^{\circ }$$$12\sin 15^{\circ }\sin 75^{\circ }$$

$-8\sin 15^{\circ }\sin 105^{\circ }$$-8\sin 15^{\circ }\sin 105^{\circ }$$$-8\sin 15^{\circ }\sin 105^{\circ }$$