Answer:
−4304
Step-by-step explanation:
1. The given determinant is :
![\begin{vmatrix}7 &31 \\ 142& 14\end{vmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bvmatrix%7D7%20%2631%20%5C%5C%20%20142%26%2014%5Cend%7Bvmatrix%7D)
We need to find its determinant . It can be solved as follows :
![\begin{vmatrix}7 &31 \\ 142& 14\end{vmatrix}=7(14)-142(31)\\\\=-4304](https://tex.z-dn.net/?f=%5Cbegin%7Bvmatrix%7D7%20%2631%20%5C%5C%20%20142%26%2014%5Cend%7Bvmatrix%7D%3D7%2814%29-142%2831%29%5C%5C%5C%5C%3D-4304)
So, the value of determinant is equal to −4304.
499-424.15=74.85
499:100=4.99
74.85:4.99=15 is the percent of the discount
100-15=85 is the percent of the original price that you pay
It's 248.3333 (but with the 3s repeating)