I don't know what you mean by factoring by grouping, but to factor thisOriginally Posted byArbitur

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:

.

RonL