posted by jamie .
perform the subtraction
I factored it to ...
2(4a+b)/( (2a-b)(4a+3b) ) - (a+2b)/( a(16a - b^2) )
nothing divides out, no duplication of factors,
you might just as well do
[ (8a+2b)(16a^2 - ab^2) - (a+2b)(8a^2 + 2ab - 3b^2) ] / [(8a^2 + 2ab - 3b^2)(16a^2 - ab^2) ]
expand and hope for the best
I suspect some sort of typing error.