Question 1126432
<pre>
You just need to add the two numbers in the numerator and then
reduce the fraction:

{{{matrix(11,1,
(4a^2 - a^3)/a^4,
"",

 (4(-3)^2 - (-3)^3)/(-3)^4,
"",
(4(9) - (-27))/(-3)^4,
"",
(36 +27)/81,
"",
63/81,
"",
7/9
)}}}

Edwin</pre>