How do you factor ab plus 3a-2b-6?

Answer 1

(a - 2)(b + 3)

Answer 2

If a polynomial has four terms, you can sometimes factor it by grouping it, and factoring one part at a time. You may have to experiment to find the correct combination (and, of course, it is possible that this method doesn't work at all). In this case:

ab + 3a - 2b - 6

= (ab + 3a) - (2b + 6)

= a(b + 3) - 2(b + 3)

= (a - 2)(b + 3)

Note the common factor, (b + 3), in the third step. If you don't get this common factor, you can't continue, and may have to try other grouping combinations.