Выполни задание

Упрости выражение:

1. \(\dfrac{\sin(45 \degree +\alpha)-\cos(45 \degree +\alpha)}{\sin(45 \degree +\alpha)+\cos(45 \degree +\alpha)}\) ;

2. \(\dfrac{\sin 21 \degree \cos 28 \degree +\cos 21 \degree \sin 28 \degree}{\cos 18 \degree \cos 31 \degree - \sin 18 \degree \sin 31 \degree}\) .