Question 705260
<pre>
{{{matrix(2,1,
"",
8^(-4/3))}}}

Change 8 to 2³

{{{matrix(2,1,
"",
(2^3)^(-4/3))}}}

Multiply exponents

{{{matrix(2,1,
"",
2^(  3(  expr(-4/3)  )) )}}}

Cancel the 3's in the exponent

{{{matrix(2,1,
"",
2^(  cross(3)(  expr(-4/cross(3))  )) )}}}

So we have

{{{matrix(2,1,
"",
2^(-4) )}}}

Bring negative exponent to the denominator as a positive exponent

{{{1/2^4}}}

{{{1/16}}}

Edwin</pre>