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.