one of the factoring that I saw in the net was factor
6bc - 9c² - 12cd - 8be + 12ce +16de
...the "clue" you need to recognize is that the coefficients of the first three terms have a common factor...and the coefficients of the last three terms have a common factor...and, the ratios are constant...so, group accordingly...
(6bc - 9c^2 - 12cd) - (8be - 12ce - 16de) = 3c(2b - 3c - 4d) - 4e(2b - 3c - 4d) =
(2b - 3c - 4d)(3c - 4e)
the above is correct and it was luck that grouping was there but what is luck is not there
then see that highest power of c is 2 and keep them in descending order
6bc - 9c² - 12cd - 8be + 12ce +16de
= - 9c² + 6bc - 12cd + 12ce - 8be + 16de
now you can factor as quadratic in c eliminating the luck factor
= - 9c² - + 6c( b - 2d + 2e) -8e(b- 2d)
= - 9c² - + 6c(( b - 2d) + 2e)) -8e(b- 2d)
letting b - 2d = a we get
= - 9c^2 + 6c(a + 2e) - 8ea
= - 9c^2 + 6ca + 12ec - 8ea
= - 3c(3c - 2a) + 4e(3c-2a)
= (3c-2a)(4e - 3c)
= (3c-2b+4d)(4e-3c)
which is same as 1st one
I do not mean to say that 2nd one is preferable to 1st but 2nd one can be used when 1st one does not work
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