12d^2 + 4d - 1
Check if splitting the middle term is possible.
List factors of -12.
1 * -12
-1 * 12
2 * -6
-2 * 6 (these digits satisfy the criteria for splitting the middle term.)
Split the middle term.
12d^2 - 2d + 6d - 1
Factor binomials.
2d(6d - d) + 1(6d - d)
Rearrange binomials.
2d + 1(6d - 2)
(6d - 2)(2d + 1) is the fully factored form of the original expression.
