a) Ta có: \(x=\dfrac{\sqrt[3]{10+6\sqrt{3}}\cdot\left(\sqrt{3}-1\right)}{\sqrt{5}+1-\sqrt{5}}\)
\(=\dfrac{\left(\sqrt{3}+1\right)\left(\sqrt{3}-1\right)}{1}\)
=2
Thay x=2 vào P, ta được:
\(P=\left(12\cdot2^2+4\cdot2-55\right)^{2017}\)
\(=1^{2017}=1\)