Question

How do you factor by grouping `3ab - b - 4 + 12a`?

Answer 1

`3ab-b-4+12a = (3a-1)(b+4)`

Reorder as `3ab - b +12a-4`
This is `b(3a-1) +4(3a-1)`
Which is `(3a-1)(b+4)`