Question 59937
The given expression is: 


a. rs(8) - 3 rs(2a^2) 


This can be written as: 


a. rs(4 * 2) - 3 rs(2) . rs(a^2)


a . rs(4) . rs(2) - 3 rs(2). a 


a . 2 . rs(2) - 3a rs(2) 


2a rs(2) - 3a rs(2)


Taking a rs(2) as a common factor (or subtracting,since they are like terms) we get: 


a rs(2) [ 2 - 3]


==>  - a rs(2) 


Hence, the solution.