Factoring by grouping: 8ax2a+4bxb
Group the terms as follows:
(8ax2a)+(4bxb)
Factor 2a out of the first two terms and b out of the second two terms
2a(4x1) + b(4x1)
Now factor (4x1) out of both terms to get the fully factored expression
(2a+b)(4x1)
Check:
(2a+b)(4x1) = 8ax2a+4xbb

You could also choose another grouping, Instead of
(8ax2a)+(4bxb)
Group the terms as follows:
(8ax+4bx)  (2a+b)
Factor 4x out of the first terms
4x(2a+b)  (2a+b)
Now factor out (2a+b)
(2a+b)(4x1) > same answer as before
4/16/2014

Philip P.