Splitting the middle term:
The middle term in the polynomial is
. This must be expressed as a sum of two terms such that the product of their coefficients is equal to the product of 2 and 3 (coefficient of x2 and the constant term)
−5 can be expressed as, as
Thus,
Now, identify the common factors in individual groups
Taking (x−1) as the common factor, this can be expressed as: