2 x 117
3 x 78
6 x 39
9 x 26
13 x 18
408 round to the nearest tenth: 410
$12.80 is your answer.. see all you needed to do was divide $2.40 by three.. as that is one oz you would only then multiply by twelve for your answer.
We can write the system in the following form:
![\left[\begin{array}{cccc}5&-4&4&2\end{array}\right] \left[\begin{array}{c}x_1\\x_2\\x_3\\x_4\end{array}\right] =b](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D5%26-4%264%262%5Cend%7Barray%7D%5Cright%5D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx_1%5C%5Cx_2%5C%5Cx_3%5C%5Cx_4%5Cend%7Barray%7D%5Cright%5D%20%20%3Db)
The above system is equivalent to the following equation:

Of course, the above system has solution for any values of b since there is one equation and four variable, there is infinite number of solution each time.