Question 774017
<pre>
{{{log(a,20) -log(a,15) + expr(1/2)log(a,9/16)}}}

{{{matrix(2,1,

"",
log(a,20)-log(a,15) + log(a,(9/16)^(1/2)) )}}}

{{{log(a,20)-log(a,15) + log(a,sqrt(9/16))}}}

{{{log(a,20)-log(a,15) + log(a,3/4)}}}

{{{log(a,20)-log(a,15) + log(a,3)-log(a,4)}}}

{{{log(a,4*5)-log(a,3*5) + log(a,3)-log(a,4)}}}

{{{log(a,4*5)-log(a,3*5) + log(a,3)-log(a,4)}}}

{{{log(a,4)+log(a,5)-(log(a,3)+log(a,5)) + log(a,3)-log(a,4)}}}

{{{log(a,4)+log(a,5)-log(a,3)-log(a,5) + log(a,3)-log(a,4)}}}

{{{cross(log(a,4))+cross(log(a,5))-cross(log(a,3))-cross(log(a,5)) + cross(log(a,3))-cross(log(a,4))}}}

Answer: 0

Edwin</pre>