$\left ( \sqrt{ 6 } + \sqrt{ \color{#FF6800}{ 12 } } \right ) \sqrt{ 2 } - \sqrt{ 3 }$
$ $ Organize the part that can be taken out of the radical sign inside the square root symbol $ $
$\left ( \sqrt{ 6 } + \color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } \right ) \sqrt{ 2 } - \sqrt{ 3 }$
$\left ( \sqrt{ \color{#FF6800}{ 6 } } \color{#FF6800}{ + } \color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } \right ) \sqrt{ \color{#FF6800}{ 2 } } - \sqrt{ 3 }$
$ $ Multiply each term in parentheses by $ \sqrt{ 2 }$
$\sqrt{ \color{#FF6800}{ 6 } } \sqrt{ \color{#FF6800}{ 2 } } + \left ( \color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } \right ) \sqrt{ \color{#FF6800}{ 2 } } - \sqrt{ 3 }$
$\sqrt{ \color{#FF6800}{ 6 } } \sqrt{ \color{#FF6800}{ 2 } } + \left ( 2 \sqrt{ 3 } \right ) \sqrt{ 2 } - \sqrt{ 3 }$
$ $ Calculate multiplication of root $ $
$\color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } + \left ( 2 \sqrt{ 3 } \right ) \sqrt{ 2 } - \sqrt{ 3 }$
$2 \sqrt{ 3 } + \left ( \color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } \right ) \sqrt{ \color{#FF6800}{ 2 } } - \sqrt{ 3 }$
$ $ Get rid of unnecessary parentheses $ $
$2 \sqrt{ 3 } + \color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } \sqrt{ \color{#FF6800}{ 2 } } - \sqrt{ 3 }$
$2 \sqrt{ 3 } + \color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } \sqrt{ \color{#FF6800}{ 2 } } - \sqrt{ 3 }$
$ $ Simplify the expression $ $
$2 \sqrt{ 3 } + \color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 6 } } - \sqrt{ 3 }$
$\color{#FF6800}{ 2 } \sqrt{ \color{#FF6800}{ 3 } } + 2 \sqrt{ 6 } \color{#FF6800}{ - } \sqrt{ \color{#FF6800}{ 3 } }$
$ $ Calculate between similar terms $ $
$\color{#FF6800}{ 1 } \sqrt{ \color{#FF6800}{ 3 } } + 2 \sqrt{ 6 }$
$\color{#FF6800}{ 1 } \sqrt{ 3 } + 2 \sqrt{ 6 }$
$ $ Multiplying any number by 1 does not change the value $ $
$\sqrt{ 3 } + 2 \sqrt{ 6 }$