Answer:
[tex]14\sqrt{3}-8\sqrt{5}[/tex]
Step-by-step explanation:
we have
[tex]2\sqrt{20}-4\sqrt{45}+7\sqrt{12}[/tex]
we know that
[tex]2\sqrt{20}=2\sqrt{2^{2}5} =2(2)\sqrt{5}=4\sqrt{5}[/tex]
[tex]4\sqrt{45}=4\sqrt{3^{2}5} =4(3)\sqrt{5}=12\sqrt{5}[/tex]
[tex]7\sqrt{12}=7\sqrt{2^{2}3} =7(2)\sqrt{3}=14\sqrt{3}[/tex]
substitute the values in the expression above
[tex]4\sqrt{5}-12\sqrt{5}+14\sqrt{3}[/tex]
Combine like terms
[tex]14\sqrt{3}-8\sqrt{5}[/tex]