Before you start, please make sure that you understand the concept of a Highest Common Factor (HCF). If not, go to the HCF topic

Count the terms. We have 2 terms here, $4e$ and $4$.

Look for the HCF of the terms, in this case, 4.

Write the HCF down followed by the open bracket symbol, $4($.

Divide each term by the HCF, taking note of the signs. $4e \div 4 = e$ and $4 \div 4 = 1$.

Write down the divided terms in the bracket.

As before, we look for the HCF of the two terms. In this case, there will be 2 parts to the HCF, a numerical bit and an $x$ bit. You should do this in two moves: the biggest number which is a factor of the terms is $2$. The letter factor is $x$. The HCF is the product of the 2, which is $2x$.

Divide both terms by the HCF and write down the answer in the form $HCF \times (Quotient1 \pm Quotient 2)$.

Note that the sign between the terms. If the HCF is positive, as here, the sign will be preserved. If it is negative, the sign in the bracket will change.

Number HCF $= 4$, letter HCF $= pq$, so full HCF $= 4pq$.

Once you have finished, it is always important to look again at the terms in the brackets and see if any more factorising can be done. If so, complete the factorisation before writing down the final answer.

Below is an possible example

$\begin{aligned} &24p^2qr+4p^2q-8pqr\\ &=2p(12qpr+2pq-4qr)\\ &=2p \times 2q(6pr+p-2r)\\ &=4pq(6pr+p-2r) \end{aligned}$

In most situations, you should go back and do the factorisation properly, in the most efficient way. In an examination, it is probably best to leave your working as above.