Answer
a) $11*\sqrt 5/12$
b) $\sqrt[3]{3x}/6$
Work Step by Step
a)
$\sqrt{20}/3 + \sqrt 5 /4$
$4*\sqrt{20}/3*4 + 3*\sqrt 5 /4*3$
$4*\sqrt{20}/12 + 3*\sqrt 5 /12$
$(4*\sqrt {20} + 3\sqrt 5)/12$
$(4*\sqrt {4*5} + 3\sqrt 5)/12$
$(4*\sqrt 4*\sqrt 5 + 3\sqrt 5)/12$
$(4*2*\sqrt 5 + 3\sqrt 5)/12$
$(8*\sqrt 5 + 3\sqrt 5)/12$
$11*\sqrt 5/12$
b)
$\sqrt[3]{24x/27} - \sqrt[3]{3x}/2$
$\sqrt[3]{24x/3^3} - \sqrt[3]{3x}/2$
$\sqrt[3]{24x}/3 - \sqrt[3]{3x}/2$
$2*\sqrt[3]{24x}/3*2 – 3*\sqrt[3]{3x}/2*3$
$2*\sqrt[3]{24x}/6 – 3*\sqrt[3]{3x}/6$
$2*\sqrt[3]{8*3x}/6 – 3*\sqrt[3]{3x}/6$
$2*\sqrt[3]{3x}*\sqrt[3]{8}/6 – 3*\sqrt[3]{3x}/6$
$2*\sqrt[3]{3x}*2/6 – 3*\sqrt[3]{3x}/6$
$4*\sqrt[3]{3x}/6 – 3*\sqrt[3]{3x}/6$
$\sqrt[3]{3x}/6$