Verified Answer :

AL2006

First, to make everything easier,divide each side by 2 :

x  =  2a + 2b

There's the solution for ' x '.

Now, if you want it solved for  ' a ' , then subtract  ' 2b '  from each side :

x - 2b  =  2a

and divide each side by  2  :      a  =  1/2 (x - 2b)

and if you want it solved for  ' b '  then subtract  ' 2a '  from each side :

x - 2a  =  2b

and divide each side by  2 :        b  =  1/2 (x - 2a) .