[tex] \bf 4 \sqrt{20} + \sqrt{12} = [/tex]
[tex] \bf 4 \sqrt{{2}^{2} \cdot5 } + \sqrt{{2}^{2} \cdot3 } = [/tex]
[tex]\bf 4\cdot2\sqrt{5 } + 2\sqrt{3} = [/tex]
[tex] \boxed{\bf 4\cdot(4\sqrt{5} + \sqrt{3 } )}[/tex]
