Solve for x :

sin (x + 10°) = $\dfrac{1}{2}$

sin (x + 10°) = $\dfrac{1}{2}$

⇒ sin (x + 10°) = sin 30°

So, x + 10° = 30°

⇒ x = 30° - 10° = 20°

Hence, x = 20°.