Answer:
Step-by-step explanation:
Since it is a geometric sequence each term will be a specific multiple of the term preceding it, called the common ratio...
126/42=378/126=1134/378=3
The sequence is a(n)=a(3)^(n-1) and we know the second term is 42 so:
42=a(3)^(2-1)
42=3a
a=14
So the first term is 14.
The Answer: (-b + 15) (15 - b)
Answer: ![A^{-1}=\left[\begin{array}{cc}\frac{3}{2}&-\frac{1}{2}\\-2&1\end{array}\right]](https://tex.z-dn.net/?f=A%5E%7B-1%7D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D%5Cfrac%7B3%7D%7B2%7D%26-%5Cfrac%7B1%7D%7B2%7D%5C%5C-2%261%5Cend%7Barray%7D%5Cright%5D)
<u>Step-by-step explanation:</u>
![\left[\begin{array}{cc}2&1\\4&3\end{array}\right]=\left[\begin{array}{cc}1&0\\0&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%261%5C%5C4%263%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%260%5C%5C0%261%5Cend%7Barray%7D%5Cright%5D)
![\dfrac{1}{2}Row\ 1\rightarrow\left[\begin{array}{cc}1&\frac{1}{2}\\4&3\end{array}\right]=\left[\begin{array}{cc}\frac{1}{2}&0\\0&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B2%7DRow%5C%201%5Crightarrow%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%26%5Cfrac%7B1%7D%7B2%7D%5C%5C4%263%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D%5Cfrac%7B1%7D%7B2%7D%260%5C%5C0%261%5Cend%7Barray%7D%5Cright%5D)
![Row\ 2 -4 \ Row\ 1\rightarrow \left[\begin{array}{cc}1&\frac{1}{2}\\0&1\end{array}\right]=\left[\begin{array}{cc}\frac{1}{2}&0\\-2&1\end{array}\right]](https://tex.z-dn.net/?f=Row%5C%202%20-4%20%5C%20Row%5C%201%5Crightarrow%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%26%5Cfrac%7B1%7D%7B2%7D%5C%5C0%261%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D%5Cfrac%7B1%7D%7B2%7D%260%5C%5C-2%261%5Cend%7Barray%7D%5Cright%5D)
![Row\ 1-\dfrac{1}{2}\ Row\ 2 \rightarrow \left[\begin{array}{cc}1&0\\0&1\end{array}\right]=\left[\begin{array}{cc}\frac{3}{2}&-\frac{1}{2}\\-2&1\end{array}\right]](https://tex.z-dn.net/?f=Row%5C%201-%5Cdfrac%7B1%7D%7B2%7D%5C%20Row%5C%202%20%5Crightarrow%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%260%5C%5C0%261%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D%5Cfrac%7B3%7D%7B2%7D%26-%5Cfrac%7B1%7D%7B2%7D%5C%5C-2%261%5Cend%7Barray%7D%5Cright%5D)
17/7 cannot be put into a whole number, but it can be put into decimal form. The estimated decimal number is 2.43. You just divide 17 by 7 and then round.
