Originally Posted by

**xivivx** By best I mean best for you. I posted this thread to find out different ways people use. I know what I've been taught is popular according to my teacher.

My way is:

Example:

3a^2+10a+7

write the first and last numbers. The middle number "10a" is what we will divide into two numbers.

3a^2+ ______+_______+7

Multiple 3 by 7= 21.

Our goal is similar to a normal trinomial without a leading coefficient more than one now. We need to find a number that when multiplied is 21 and added 10. Eventually, the numbers 3 and 7 will come up. Better to go in chronological order for those who do not know.

3a^2+3a+7a+7

Now use grouping method.

3a(a+1) 7(a+1)

Take the numbers 3a and 7... put them in (3a+7)

(a+1) (a+1) is similar to doing it with (3a+7)

answer: (3a+7)(a+1)

=(3a+7) (a+1)

This is how I do it. It might not make sense for you, but it does for me.

Now, what's your way?