Use Cramers rule to solve the following system

Question

x + 5y = 7

 

3x - 4y = 2

Answer 1

System determinant is

1  5

3  -4  (enclosed in vertical bars); system determinant value is -4 - 14 = -19.

 

Determinant-for-x:

7  5

2  -4 & its value is -28 - 10 = -38

 

Therefore x = -38/-19 = 2.

 

By substitution, I find that y = 1.  

 

Of course, you've been directed to do all the work using determinants; I leave the y work to you.