SOLUTION: I am not understanding how to solve for x in a matrix. The problem I am looking at is: SOLVE FOR X, GIVEN THAT |-5 0 -1| |2 1 0|=4 |x 3 0| I don't even really know where

Algebra ->  Matrices-and-determiminant -> SOLUTION: I am not understanding how to solve for x in a matrix. The problem I am looking at is: SOLVE FOR X, GIVEN THAT |-5 0 -1| |2 1 0|=4 |x 3 0| I don't even really know where       Log On


   



Question 770534: I am not understanding how to solve for x in a matrix. The problem I am looking at is: SOLVE FOR X, GIVEN THAT
|-5 0 -1|
|2 1 0|=4
|x 3 0|
I don't even really know where to start with this and my book isn't helping!

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
I am not understanding how to solve for x in a matrix. The problem I am looking at is: SOLVE FOR X, GIVEN THAT
|-5 0 -1|
|2 1 0|=4
|x 3 0|
----------
Assuming 4 is the determinant (nothing else makes sense),
Expand by minors.
---
x*(0+1) - 3*(0+2) + 0 = 4
x - 6 = 4
x = 10