hi please help me
Find the sum of the first 8 terms of the arithmetic sequence 30, 33, 36, 39, 42, 45, . . .
thank you...
as always,
Sn = 8/2 (2a+(n-1)d)
So in this case,
S8 = 8/2 (2*30 + 7*3)
Looks like you need to do the math, 2pi! How did you get 225?
So what is the final answer?
To find the sum of the first 8 terms of an arithmetic sequence, you can use the formula for the sum of an arithmetic series. The formula is given by:
Sn = (n/2)(2a + (n-1)d)
Where:
Sn is the sum of the first n terms,
n is the number of terms,
a is the first term,
d is the common difference between consecutive terms.
In this case, the first term (a) is 30, and the common difference (d) is 3 (since each term increases by 3). We want to find the sum of the first 8 terms (n = 8).
Plugging these values into the formula:
S8 = (8/2)(2 * 30 + (8-1) * 3)
Simplifying:
S8 = (4)(60 + 7 * 3)
S8 = (4)(60 + 21)
S8 = (4)(81)
S8 = 324
Therefore, the sum of the first 8 terms of the arithmetic sequence is 324.