[tex] a.\\8:\dfrac{1}{2}\cdot3=8\cdot\dfrac{2}{1}\cdot3=8\cdot2\cdot3=16\cdot3=48\\\\b.\\3\sqrt{50-1}=3\sqrt{49}=3\cdot7=21\\\\c.\\\dfrac{(5+2)(-8)}{(-2)^3-3}=\dfrac{7(-8)}{-8-3}=\dfrac{-56}{-11}=\dfrac{56}{11}=5\dfrac{1}{11} [/tex]
