Please help! Need to figure this out for tomorrow

[keith22]

I am going to soon be writing a math test to upgrade my high school grades for a college course in Canada. Here is my question that I need help solving. More than anything, I need to see the steps involved in solving. I already know the answer is 2. Thanks so much!



Here is what I keep coming up with that is incorrect. Answer should be 2.

 

[keith22]

Answer found! I was treating the 2 in the cube root sign as a multiplying factor when it is not. So the answer was 6-4, not 12-8. Thanks anyway

 

[HallsofIvy]

That is NOT cube root sign, it is a square root. Even just $\displaystyle \sqrt{x}$ would be interpreted as square root but here they were trying to be clearer- which confused you!