1) \(x^4+2x^2\sqrt{3}+3=\left(x^2+\sqrt{3}\right)^2\)
2) \(5-4a=\left(\sqrt{5}-2\sqrt{a}\right)\left(\sqrt{5}+2\sqrt{a}\right)\)
3) \(-4\sqrt{a^3}+16\sqrt{a}=-4a\sqrt{a}+16\sqrt{a}=-4\sqrt{a}\left(a-4\right)=-4\sqrt{a}\left(\sqrt{a}-2\right)\left(\sqrt{a}+2\right)\)
4) \(\left(3\sqrt{a}\right)^3-8b^3=\left(3\sqrt{a}-2b\right)\left(9a+6b\sqrt{a}+4b^2\right)\)
5) \(a\sqrt{b}-b\sqrt{a}=\sqrt{ab}\left(\sqrt{a}-\sqrt{b}\right)\)
6) \(a-5\sqrt{a}-6=\left(\sqrt{a}-6\right)\left(\sqrt{a}+1\right)\)
7) \(a+\sqrt{a}-12=\left(\sqrt{a}-4\right)\left(\sqrt{a}+3\right)\)