How do you factor by grouping #28s^2 - 37s - 21#?
There are 2 methods.
1. Factoring AC method (factoring by grouping) .
Find 2 numbers b1 and b2 that satisfy these 2 conditions:
( since their sum is
Next factor by grouping:
f(x) = (4x - 7)(7x + 3)
2. The new AC method to factor a trinomial f(x)
First convert trinomial (1) to
Compose factor pairs of
and apply the Rule of Sign for Real Roots.
This sum is
Then, the factored form is:
This new AC Method avoids the lengthy factoring by grouping.