Question

Please help!!! I will medal the best response!!!
Given the system of equations, what is the value of the y-determinant?

3x+y-10=0
4x-y-4=0

A)-28
B)-14
C)28

What did I do wrong and how do I fix it?
Here is how I did it...

Answer 1

The answers A, but how? I did the problem twice and got \[\frac{ 52 }{ 7 }\] Both times. Here's how I did it:

I first convered them to
4x+(-y)=4
3x+y=10

Then:



Then:



So after all of that it ends up to be \[7 \frac{ 3 }{ 7}\]
What did I do wrong?