code code

A =$\Large{\frac{\sqrt{ x }}{\sqrt {x - 2}} + \frac{\sqrt {x - 1}} {\sqrt {x + 2}} + \frac{\sqrt {x - 10}} {x - 4}}$ $\left( {x \ge 0,x \ne 4} \right)$
$B = \left( {13 - 4\sqrt 3 } \right)\left( {7 + 4\sqrt 3 } \right) - 8\sqrt {20 + 2\sqrt {43 + 24\sqrt 3 } }$
$\begin{array}{l} a){x^2} - 8x + 15 = 0 b)2{x^2} - \sqrt 2 x - 2 = 0 c){x^4} - 5{x^2} - 6 = 0\\ d)\left\{ \begin{array}{l} 2x + 5y = - 3\\ 3x - y = 4 \end{array} \right. \end{array}$
$4(\sin 3x - c{\rm{os2x}}) = 5({\mathop{\rm s}\nolimits} {\rm{inx - 1)}}$