Factoring by grouping: 8ax-2a+4bx-b
Group the terms as follows:
(8ax-2a)+(4bx-b)
Factor 2a out of the first two terms and b out of the second two terms
2a(4x-1) + b(4x-1)
Now factor (4x-1) out of both terms to get the fully factored expression
(2a+b)(4x-1)
Check:
(2a+b)(4x-1) = 8ax-2a+4xb-b
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You could also choose another grouping, Instead of
(8ax-2a)+(4bx-b)
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)(4x-1) --> same answer as before