Question

Given the system of equations, what is the value of the system determinant?
x + y = 8
x - y = 10

Answer 1

To find the determinant of a 2x2 matrix:

\[A = \left[\begin{matrix}a & b \\ c & d\end{matrix}\right]\\
|A|=det(A)=ad-cb\]

Answer 2

I'd actually forgotten how to do this since it's been so long, and it literally took a 2 second Google search ;)

Answer 3

a and c is the value of x and b and d is the value of y