factor the polynomial

[Desan65]

Factor each polynomial: -6mn + 4m + 18n - 12
Please solve step-by step. I get the positives and negatives incorrectly

 

[Desan65]

2(-3mn + 2m + 9n - 6)
-3n(m-3) + 2 (m-3)
My answer: 2(m-3) (2-3n)

But the book says the answer is -2(m-3) (3n-2)!

 

[Desan65]

Thanks!

 

[Desan65]

Still some problems!

I still seem to get the positives and negatives mixed up.
Problem: 2b²+10b+12

The factors are 12 and -2

2b²+12b-2b+12
2b(b+6) -2(b-6)
the last equation should be (b+6) same as the first one, but why?