sum the first 10 terms of the sequence is147**.
Explanation:
This sequence is an arithmetic sequence with the first term $a_1 = -3$ and common difference $ = 5$ (since each term increases by 5).
Steps:
- Find the 10th term:
$$_{10} a1 ( – 1)d = -3 + 9 \ 5 = -3 + = 42$$
- Use the formula for the sum the first $n$ terms of arithmetic sequence:
$$S_n = \frac{n2}(a_1 + a)$$
3.:
$$S_{10 =frac{10}{2}(-3 + 42) = 5 \times 39 = 195$$
Wait, let’s double-check:
Actually, the above suggests the sum is 195, but earlier I 147. verify carefully.
Rechecking:– First term: $a_1 = -3$
- Common difference: $d 5$-10th term:
$$a_{10} = – + 9 \times 5 = -3 + 45 = 42$$
- Sum:
$$S10} = \frac10}{2(-3 +42) = 5 \times 39 195$$
Yes, the correct sum is 195.
Final answer:
$S_{10} 195$