What is the first step when using the 'factoring by grouping' method?

When applying the 'factoring by grouping' method, the first step involves finding the greatest common factor (GCF) of all the terms in the expression. This is crucial because identifying the GCF allows you to factor it out from the expression, simplifying it into a form that is easier to manipulate and group.

Once the GCF is factored out, you can then proceed to group the remaining terms in pairs or sets that share common factors. This eventually leads to further factoring and solving the expression. Without establishing the GCF initially, the subsequent steps may become more complicated and less systematic.

Rearranging terms may be necessary after factoring out the GCF, but it is not the initial step. Setting the expression equal to zero is relevant in the context of solving equations but is not part of the initial factoring process. Substituting a variable is also not relevant at this stage in factoring; this technique is typically used later when dealing with polynomial expressions or equations. Thus, starting with finding the GCF sets the stage for successful factoring by grouping.