Question 126314
{{{(16x^8)^-0.75}}} 
:
The reciprocal will get rid of the negative exponent
{{{1/((16x^8)^0.75)}}}
:
When raising one power to another power multiply the exponents:
{{{1/(16^.75x^(8*.75))}}}
:
{{{1/(16^.75x^6)}}}
:
Change the decimal exponent to a fraction 
{{{1/(16^(3/4)x^6)}}}
:
The 4th root of 16 is 2
{{{1/(2^3x^6)}}}
:
{{{1/(8x^6)}}}