B. The independent quantity is definitely not the words cause' of you think about it the number of words depends on the number of minutes.
Make into matrix
![\left[\begin{array}{ccc}2&1&1\\1&-3&-1\\4&5&2\end{array}\right] = \left[\begin{array}{ccc}-2\\14\\-4\end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%261%261%5C%5C1%26-3%26-1%5C%5C4%265%262%5Cend%7Barray%7D%5Cright%5D%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2%5C%5C14%5C%5C-4%5Cend%7Barray%7D%5Cright%5D%20%20%20)
accoring to cramer's rule
replace the y collum with eh constant collumn and find the detterminant
![\left[\begin{array}{ccc}2&-2&1\\1&-14&-1\\4&-4&2\end{array}\right]](https://tex.z-dn.net/?f=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%26-2%261%5C%5C1%26-14%26-1%5C%5C4%26-4%262%5Cend%7Barray%7D%5Cright%5D)
det
![2 \left[\begin{array}{ccc}14&-1\\-4&2\end{array}\right]-(-2) \left[\begin{array}{ccc}1&-1\\4&2\end{array}\right]+1 \left[\begin{array}{ccc}1&14\\4&-4\end{array}\right] ](https://tex.z-dn.net/?f=%202%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D14%26-1%5C%5C-4%262%5Cend%7Barray%7D%5Cright%5D-%28-2%29%20%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%26-1%5C%5C4%262%5Cend%7Barray%7D%5Cright%5D%2B1%20%20%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%2614%5C%5C4%26-4%5Cend%7Barray%7D%5Cright%5D%20%0A%0A)
dunno wat fraction is
pick last option
The one on the left represent 5x2 =10 and the one on the right represent 5+2=7 :)
The next multiples of 1/5 are 2/5,3/5,4/5,5/5=1