Originally Posted by
jhonwashington Hello.
I'm asked to find the value of the following determinant using cramer's rule.
0 , 1 , 2
4, -5 , 8
8, 0 , -9
so I repeat the first two columns
0 1 2 0 1
4 -5 8 4 -5
8 0 -9 8 0
and then I multiply diagonally and add and then subtract and I get
0+64+0- (-80+0-36)=
64 +80-36 = 108
so My answer is 108, but all calculators tell me that my answer should be 180, why? I suspect that I should be adding 36 in that case I would get 180, but I don't see how I could be adding 36 if 36 has a negative sign. please help me.