Answer: ![14*\sqrt[3]{x^{10}}](https://tex.z-dn.net/?f=14%2A%5Csqrt%5B3%5D%7Bx%5E%7B10%7D%7D)
Step-by-step explanation:
First, let's remember the rules:
![x^{1/n} = \sqrt[n]{x}](https://tex.z-dn.net/?f=x%5E%7B1%2Fn%7D%20%3D%20%5Csqrt%5Bn%5D%7Bx%7D)
such that:
![\sqrt[n]{x^m} = x^{m/n}](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%7Bx%5Em%7D%20%3D%20x%5E%7Bm%2Fn%7D)


Now we have the equation:
![4*\sqrt[3]{x^{10}} + 5*x^3*\sqrt[3]{8*x}](https://tex.z-dn.net/?f=4%2A%5Csqrt%5B3%5D%7Bx%5E%7B10%7D%7D%20%2B%205%2Ax%5E3%2A%5Csqrt%5B3%5D%7B8%2Ax%7D)
First, let's rewrite the roots as we saw above:
![4*x^{10/3} + 5*x^3*\sqrt[3]{8}*x^{1/3} = 4*x^{10/3} + 5*\sqrt[3]{8}*x^{3 + 1/3}](https://tex.z-dn.net/?f=4%2Ax%5E%7B10%2F3%7D%20%2B%205%2Ax%5E3%2A%5Csqrt%5B3%5D%7B8%7D%2Ax%5E%7B1%2F3%7D%20%3D%204%2Ax%5E%7B10%2F3%7D%20%2B%205%2A%5Csqrt%5B3%5D%7B8%7D%2Ax%5E%7B3%20%2B%201%2F3%7D)
We also know that: ![\sqrt[3]{8} = 2](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B8%7D%20%3D%202)
and that: 
Replacing those two things in our equation, we get:
![4*x^{10/3} + 5*\sqrt[3]{8}*x^{3 + 1/3} = 4*x^{10/3} + 5*2*x^{10/3} = (4 + 5*2)*x^{10/3}](https://tex.z-dn.net/?f=4%2Ax%5E%7B10%2F3%7D%20%2B%205%2A%5Csqrt%5B3%5D%7B8%7D%2Ax%5E%7B3%20%2B%201%2F3%7D%20%3D%204%2Ax%5E%7B10%2F3%7D%20%2B%205%2A2%2Ax%5E%7B10%2F3%7D%20%3D%20%284%20%2B%205%2A2%29%2Ax%5E%7B10%2F3%7D)
![(4 + 10)*x^{10/3} = 14*\sqrt[3]{x^{10}}](https://tex.z-dn.net/?f=%284%20%2B%2010%29%2Ax%5E%7B10%2F3%7D%20%3D%2014%2A%5Csqrt%5B3%5D%7Bx%5E%7B10%7D%7D)
Where in the final step, I returned to the cubic root form.