Just add 12 to -7, -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12
Answer:
![S_n=3k\cdot (2k+1)=6k^2 +3k](https://tex.z-dn.net/?f=S_n%3D3k%5Ccdot%20%282k%2B1%29%3D6k%5E2%20%2B3k)
Step-by-step explanation:
k is a positive integer.
Consider an arithmetic sequence:
![a_1=2k\\ \\a_n=4k\\ \\d=1](https://tex.z-dn.net/?f=a_1%3D2k%5C%5C%20%5C%5Ca_n%3D4k%5C%5C%20%5C%5Cd%3D1)
First, find n:
![a_n=a_1+(n-1)\cdot d\\ \\4k=2k+(n-1)\cdot 1\\ \\2k=n-1\\ \\n=2k+1](https://tex.z-dn.net/?f=a_n%3Da_1%2B%28n-1%29%5Ccdot%20d%5C%5C%20%5C%5C4k%3D2k%2B%28n-1%29%5Ccdot%201%5C%5C%20%5C%5C2k%3Dn-1%5C%5C%20%5C%5Cn%3D2k%2B1)
Now, find the sum of these 2k+1 terms:
![S_n=\dfrac{a_1+a_n}{2}\cdot n\\ \\S_n=\dfrac{2k+4k}{2}\cdot (2k+1)=\dfrac{6k}{2}\cdot (2k+1)=3k\cdot (2k+1)=6k^2 +3k](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7Ba_1%2Ba_n%7D%7B2%7D%5Ccdot%20n%5C%5C%20%5C%5CS_n%3D%5Cdfrac%7B2k%2B4k%7D%7B2%7D%5Ccdot%20%282k%2B1%29%3D%5Cdfrac%7B6k%7D%7B2%7D%5Ccdot%20%282k%2B1%29%3D3k%5Ccdot%20%282k%2B1%29%3D6k%5E2%20%2B3k)
130.80 is the answer you have to multiply 120 times 1.09
Answer:
29
Step-by-step explanation:
-18 (Negative Eighteen) = A
29 (Positive Twenty Nine) = B
11 (Positive Eleven) = C
First, make A positive, and add C to it. You get B.
Now here is the equation:
-18 + (18 + 11)
-18 + (29)
11
Answer:
0+0+c=0
Step-by-step explanation: