Question

How do you factor by grouping `6ab+7a-24b-28`?

Answer 1

By looking for common factors among pairs of terms we see
`6ab -24b = (6b)(a-4)`
and
`7a-28 = (7)(a-4)`

So
`6ab+7a-24b-28`

`= (6b+7)(a-4)`