1. ## Factoring by grouping

How can I factor by grouping 10*x^2-11X-6

2. Originally Posted by vaironxxrd
How can I factor by grouping 10*x^2-11X-6
Have you tried (5x+2)(2x-3) yet ?

3. Originally Posted by Archie Meade
Have you tried (5x+2)(2x-3) yet ?
The question asked to factorise by grouping.

You need to find two numbers that multiply to give 10*(-6) = -60 and add to give -11. The numbers are -15 and 4. So break the middle term into -15x + 4x to give

10x^2 - 15x + 4x + 6

You should now be able to factorise by grouping.

4. Originally Posted by Prove It
The question asked to factorise by grouping.

You need to find two numbers that multiply to give 10*(-6) = -60 and add to give -11. The numbers are -15 and 4. So break the middle term into -15x + 4x to give

10x^2 - 15x + 4x + 6

You should now be able to factorise by grouping.
Couldn't you have left a little to the imagination ?
No ? ok

5. Originally Posted by Archie Meade
Couldn't you have left a little to the imagination ?
No ? ok
I could have if your post had given any hints on how to use the "factorising by grouping" method, instead of just giving the final answer...

6. Originally Posted by Prove It
I could have if your post had given any hints on how to use the "factorising by grouping" method, instead of just giving the final answer...
Sorry for being too subtle in my initial response.

7. This thread's getting out of hand, so I'm going to close it off.

One way to give hints that don't give away the whole package is to analyze every step of the solution, and figure out exactly where the OP'er is stuck.

In this case, the OP'er knows he wants to proceed by the method of grouping. So the first thing to ask is where is the OP'er stuck. Once you know that, you can begin a gently leading Socratic dialogue such that, hopefully, the OP'er can answer each question and perhaps jump to the next conclusion before you ask the question to lead him there.

Remember John Milton Gregory's 6th Law of Teaching: "Excite and direct the self-activities of the pupil, and as a rule tell him nothing that he can learn himself."