Step-by-step explanation:
[tex]4\sqrt{27} + 3\sqrt{12}[/tex]
First, let's rewrite the numbers inside the square roots as factors that include squares:
[tex]4\sqrt{9 * 3} + 3\sqrt{4 * 3}[/tex]
Now, we can take the square root of these squares, while keeping the remaining factor(s) inside of the square root:
[tex](4*3)\sqrt{3} + (3*2)\sqrt{3}[/tex]
[tex]12\sqrt{3} + 6\sqrt{3}[/tex]
[tex]18\sqrt{3}[/tex]