\[\sin{130{^\circ}} - \sin{10{^\circ}} =\]
\[= 2\sin\frac{120{^\circ}}{2} \cdot \cos\frac{140{^\circ}}{2} =\]
\[= 2\sin{60{^\circ}} \cdot \cos{70{^\circ}} =\]
\[= 2 \cdot \frac{\sqrt{3}}{2} \cdot \cos{70{^\circ}} = \sqrt{3}\cos{70{^\circ}}\]