1. Let's first identify the problem you are working on and the steps you have completed. 2. Since you mentioned being lost from step 4 to 5, please provide the exact problem or the expressions involved in these steps. 3. Generally, moving from step 4 to 5 involves simplification, factoring, or applying a formula. 4. If you share the expressions or equations from step 4 and step 5, I can explain the transition clearly. 5. Please provide the details so I can help you understand the missing part.