Rút gọn biểu thức\(\begin{array}{l}a)\,\,\left( {5\sqrt {48}  + 4\sqrt {27}  - 2\sqrt {12} } \right):\sqrt 3 \\b)\,\,\left( {\sqrt {{a^2} - {b^2}}  + \sqrt {\left( {a + b} \right)....

A \(\begin{array}{l}
a)\,\,\sqrt{3}\\
b)\,\,\sqrt {a - b} + \sqrt b 
\end{array}\)

B \(\begin{array}{l}
a)\,\,28\\
b)\,\,\sqrt {a - b} + \sqrt b
\end{array}\)

C \(\begin{array}{l}
a)\,\,28\\
b)\,\,\sqrt {a + b} + \sqrt b 
\end{array}\)

D \(\begin{array}{l}
a)\,\,3\sqrt{3}\\
b)\,\,\sqrt {a - b} + \sqrt b 
\end{array}\)