I don't know what you mean by factoring by grouping, but to factor thisOriginally Posted by Arbitur
we start by taking out the so:
Now we observe that this is high-school maths, so if this
is factorisable the the factors will have integer numeric terms.
Now is prime so that suggests we consider
factors of the form , for or .
The first one we try is , putting
in the expression gives zero and so is a factor.
Then doing the divisions gives us: