Verified answer

((a-8)/(a+8) - (a+8)/(a-8)):(16a/(64-a²)) = ((a-8)²-(a+8)² ) / ((a+8)(a-8))  * (64-а²)/ 16а =

=   (a²-16а+64 - a²-16а-64 ) / (a²-64)  * (64-а²)/ 16а  =

= -32а / (a²-64)  * (- (а² -64)/ 16а) = 32а/ 16а = 2