.... I don't think anyone can answer that. We don't have anything to work off of.
27 divided by 3= 9
That's a division problem right?
Sorry,
Katie
The Geometric Sequence Formula:
![a_n=a_1r^{n-1}](https://tex.z-dn.net/?f=a_n%3Da_1r%5E%7Bn-1%7D)
We have:
![a_1=-2,\ a_2=8,\ a_3=-32,\ a_4=128,\ ...](https://tex.z-dn.net/?f=a_1%3D-2%2C%5C%20a_2%3D8%2C%5C%20a_3%3D-32%2C%5C%20a_4%3D128%2C%5C%20...)
![d=\dfrac{a_{n+1}}{a_n}\to d=\dfrac{8}{-2}=-4](https://tex.z-dn.net/?f=d%3D%5Cdfrac%7Ba_%7Bn%2B1%7D%7D%7Ba_n%7D%5Cto%20d%3D%5Cdfrac%7B8%7D%7B-2%7D%3D-4)
Substitute:
![a_n=-22\cdot(-4)^{n-1}=-22\cdot(-4)^n\cdot(-4)^{-1}=-22\cdot(-4)^n\cdot\left(-\dfrac{1}{4}\right)=5.5(-4)^n](https://tex.z-dn.net/?f=a_n%3D-22%5Ccdot%28-4%29%5E%7Bn-1%7D%3D-22%5Ccdot%28-4%29%5En%5Ccdot%28-4%29%5E%7B-1%7D%3D-22%5Ccdot%28-4%29%5En%5Ccdot%5Cleft%28-%5Cdfrac%7B1%7D%7B4%7D%5Cright%29%3D5.5%28-4%29%5En)
First set is parallel - same gradient
Second set is neither - gradient is 2/6 or 1/3. It then had to be 3 for it to be perpendicular.
Hope this helps!
Answer:
the denominator of the expression is 3n-2