Final answer:
The step that is incorrect in solving the equation is factoring. Hence, option B is correct.
Step-by-step explanation:
The step that is incorrect in solving the equation is b) Factoring.
When solving an equation, factoring is not always necessary. It is only used when the equation can be simplified by factoring out common factors or using a factoring technique like the difference of squares.
However, combining like terms, solving for the variable, and simplifying the expression are important steps to solve an equation correctly.