I positive 15 and negative 15, in effect the absolute value function just removed negative signs
Answer:
![\left[\begin{array}{ccc}4&19&-5\\7&0&-14\end{array}\right] + \left[\begin{array}{ccc}-8&7&0\\-1&17&6\end{array}\right] = \left[\begin{array}{ccc}-4&26&-5\\6&17&-8\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4%2619%26-5%5C%5C7%260%26-14%5Cend%7Barray%7D%5Cright%5D%20%2B%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-8%267%260%5C%5C-1%2617%266%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-4%2626%26-5%5C%5C6%2617%26-8%5Cend%7Barray%7D%5Cright%5D)
Step-by-step explanation:
To add two matrices you just need to add the corresponding entries together. In this case, we have that:
![\left[\begin{array}{ccc}4&19&-5\\7&0&-14\end{array}\right] + \left[\begin{array}{ccc}-8&7&0\\-1&17&6\end{array}\right]=\left[\begin{array}{ccc}4-8&19+7&-5 + 0\\7-1&0+17&-14+6\end{array}\right] = \left[\begin{array}{ccc}-4&26&-5\\6&17&-8\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4%2619%26-5%5C%5C7%260%26-14%5Cend%7Barray%7D%5Cright%5D%20%2B%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-8%267%260%5C%5C-1%2617%266%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4-8%2619%2B7%26-5%20%2B%200%5C%5C7-1%260%2B17%26-14%2B6%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-4%2626%26-5%5C%5C6%2617%26-8%5Cend%7Barray%7D%5Cright%5D)
Then, we conclude that the sume of the two matrices is:
Combine like terms:
2x - x + 3
x + 3
Once there is no more simplification to be done, your final answer remains which is the above equation.
First piece:
Nathan doesn´t use= 9.8 ft - 5.2 ft=4.6 ft
Second piece:
Nathan doesn´t use=7.5 ft-6.1 ft=1.4 ft
Third piece:
Nathan doesn´t use= 12 ft.
feet of wood don´t use=4.6 ft + 1.4 ft + 12 ft=18 ft.
Answer: Nathan doesn´t use 18 feet
