S= n/2[2a + (n - 1)d]
please solve and show the steps to get there. I'm confused at how they reached the answer the book has. Thanks
If you're attempting to apply this formula in a specific question, it would help if you actually posted that question. We are not mind readers.
Sorry it was solve for a and I just can't see to figure out how they achieved the answer they got. How would you approach this. In order for me to understand I would need to see how you reached your answer.
Anyone who is up for the challenge. I would greatly appreciate it.