Q. Find the 15th term of the arithmetic sequence 5x+1,9x+7,13x+13,…Answer:
Determine Common Difference: To find the 15th term of an arithmetic sequence, we need to determine the common difference between consecutive terms and then use the formula for the nth term of an arithmetic sequence, which is an=a1+(n−1)d, where an is the nth term, a1 is the first term, and d is the common difference.
Find Common Difference: First, let's find the common difference d by subtracting the first term from the second term: (9x+7)−(5x+1)=4x+6. Then, subtract the second term from the third term: (13x+13)−(9x+7)=4x+6. Since the difference is the same, the common difference d is 4x+6.
Use Formula for 15th Term: Now, we can use the formula to find the 15th term a15. The first term a1 is 5x+1. Plugging the values into the formula, we get a15=(5x+1)+(15−1)(4x+6).