\(\left(1+\sqrt{5}\right)x+\sqrt{45}=\sqrt{320}\)
\(\Rightarrow x\left(\sqrt{5}+1\right)+3\sqrt{5}-8\sqrt{5}=0\)
\(\Rightarrow x\left(\sqrt{5}+1\right)+3\left(\sqrt{5}+1\right)-8\left(\sqrt{5}+1\right)=5\)
\(\Rightarrow\left(x-5\right)\left(\sqrt{5}+1\right)=5\)
\(\Rightarrow x-5=4-\sqrt{5}\)
\(\Rightarrow x=9-\sqrt{5}\)