Question

2x - y = 5
x + 3y = 7

What is the value of the y-determinant?

A) 7
B) 9
C) 22

Answer 1

Im pretty sure that the answer it is A. 7
because if you subtract 2 from 7 you get 5

Answer 2

The two equations are,

1. 2 x- y=5

2. x + 3 y =7

To determine the y-determinant, we will evaluate

$\begin{vmatrix} 2& 5\\  1& 7\end{vmatrix}\\\\\\=14-5=9\\\\ As,D= \begin{vmatrix} a& b\\  c& d\end{vmatrix}\\\\ D= a d - b c$

Option (B)→ 9 is correct y-Determinant.