please help this 2 sums

Answer:
Step-by-step explanation:
Sin (A + B) = Sin A *Cos B + Cos A *Sin B
Sin 75 = Sin (30 + 45)
= Sin 30 * Cos 45 + Cos 30 * Sin 45
[tex]= \dfrac{1}{2}*\dfrac{1}{\sqrt{2}}+\dfrac{\sqrt{3}}{2}*\dfrac{1}{\sqrt{2}}\\\\\\= \dfrac{1}{2\sqrt{2}}+\dfrac{\sqrt{3}}{2\sqrt{2}}\\\\= \dfrac{1+\sqrt{3}}{2\sqrt{2}}[/tex]