Bonjour,
[tex]B=\dfrac{2-\dfrac{1}{3}}{\left(\dfrac{1}{2}\right)^2}=\dfrac{\dfrac{6}{3}-\dfrac{1}{3}}{\dfrac{1}{4}}=\dfrac{\dfrac{5}{3}}{\dfrac{1}{4}}\\\\\\=\dfrac{5}{3}\times4=\boxed{\dfrac{20}{3}}[/tex]
[tex]C=-\dfrac{4\times10^{-2}\times(-5)\times10^7}{3\times10^5}\\\\=-\dfrac{4\times(-5)\times10^{(-2+7)}}{3\times10^5}=-\dfrac{-20\times10^5}{3\times10^5}=\boxed{\dfrac{20}{3}}[/tex]
[tex]D=\dfrac{\left(3+\sqrt{11}\right)^2-6\sqrt{11}}{3}\\\\=\dfrac{3^2+2\times3\times\sqrt{11}+\left(\sqrt{11}\right)^2-6\sqrt{11}}{3}\\\\=\dfrac{9+6\sqrt{11}+11-6\sqrt{11}}{3}=\dfrac{9+11}{3}=\boxed{\dfrac{20}{3}}[/tex]
