Solving for X inside of a 3X3Matrix

[smashbrohamme]

Using cramers rule.

the equation is.

x,1,2
1,x,3 all set to equal -4x
0,1,2


I made my 2x2 matrix like this

x|x,3| -1|1,3| +2|1,x|
|1,2| |0,2| |0,1|

eventually I ended up with x(2x-3)-1(2)+2(1)=-4x

condensed it down to 2x^2-3x=-4x

2x^2+1x=0
x(x+1)=0

x=0, or x=-1.

I go back to plug it in...and its wrong! :(

 

[SteamKing]

When you had your initial equation, 2x^2+x=0 and you divided by 2, you got an incorrect result.

 

[I like Serena]

2x^2+1x=0
x(x+1)=0

Little mistake in this step...