4. a₁ = 7, d = 3 Find the 6th term → a₆ = ____
Answer (1)
To find the 6th term a 6 of an arithmetic sequence, we use the formula for the n -th term of an arithmetic sequence:
a n = a 1 + ( n − 1 ) × d
Here, a 1 is the first term (which is 7), d is the common difference (which is 3), and n is the term number you want to find (which is 6 for a 6 ).
Now, substitute the given values into the formula:
a 6 = 7 + ( 6 − 1 ) × 3
First, calculate 6 − 1 :
6 − 1 = 5
Next, multiply this result by the common difference d :
5 × 3 = 15
Finally, add this result to the first term a 1 :
7 + 15 = 22
So, the 6th term of the sequence, a 6 , is 22.
