Saludos Ezequiel Ibalo
1. Se factorizan todos los radicandos
2. Se simplifican todas las raíces
3. Se operan las raíces semejantes
$$\begin{align}&\\&\Big ( -5 \sqrt {147} - \sqrt {3} -2 \sqrt {5} \Big )^2 + 3 \sqrt {80} =\\&\\&\\&\Big ( -5 \sqrt {3*7^2} - \sqrt {3} -2 \sqrt {5} \Big )^2 + 3 \sqrt {2^4*5} =\\&\\&\\&\Big ( -5*7 \sqrt {3} - \sqrt {3} -2 \sqrt {5} \Big )^2 + 3*2^2 \sqrt {5} =\\&\\&\\&\Big ( -35 \sqrt {3} - \sqrt {3} -2 \sqrt {5} \Big )^2 + 3*4 \sqrt {5} =\\&\\&\\&\Big ( -35 \sqrt {3} - \sqrt {3} -2 \sqrt {5} \Big )^2 + 12 \sqrt {5} =\\&\\&\\&\Big ( (-35-1) \sqrt {3} -2 \sqrt {5} \Big )^2 + 12 \sqrt {5} =\\&\\&\\&\Big ( -36 \sqrt {3} -2 \sqrt {5} \Big )^2 + 12 \sqrt {5} =\\&\\&\\&\Big (-36 \sqrt {3} \Big )^2 +2*\Big (-36 \sqrt {3} \Big )*\Big (- 2 \sqrt {5} \Big )+\Big (- 2 \sqrt {5} \Big )^2 + 12 \sqrt {5} =\\&\\&\\& \Big (1296 * {3} \Big ) +\Big (-72 \sqrt {3} \Big )*\Big (- 2 \sqrt {5} \Big )+\Big ( 4 * {5} \Big ) + 12 \sqrt {5} =\\&\\&\\& 3888 +144 \sqrt {3} \sqrt {5} +20 + 12 \sqrt {5} =\\&\\&\\&3908+144 \sqrt {3} \sqrt {5} + 12 \sqrt {5} =\\&\\&\\&144 \sqrt {3} \sqrt {5} + 12 \sqrt {5} = - 3908\\&\\&\\&\sqrt {5} \ (144 \sqrt {3} + 12 ) = - 3908\\&\\&\\&\\&\\&\\&\end{align}$$