Question

How to know the splitting numbers in splitting the middle term method ?? ( especially big no's )

Answer 1

1. You should be good in multiplication and know tables of numbers up to 30.
2. When you solve enough questions you will be able to separate the middle term just by looking at it though it has big coefficients.
3. Ask yourself : which are the two terms whose sum is the middle term and product is the constant term ? Follow this approach. It helps.

If My problem is finding the two numbers that times together to make -36 and add together to make -5.
ThenWith lower numbers a manual approach is an option, just listing from 1 up:
1x36
2x18
3x12
4x9
6x6
Taking 4 and 9 only gives sum -5 that is -9 and 4
-9*4=-36
-9+4=-5

If the 'c' term is negative then one factor will be positive, the other negative.
If the C term is positive they will both have the same sign (+/-)