Cramer's Rule for 3x3 Systems 1

Cramer's Rule for 3 x 3's works, pretty much, the same way it does for 2 x 2's -- it's the same pattern.

Let's solve this one:

First, find the determinant of the coefficient matrix:

(I'm just going to crunch the determinants without
showing the work -- you should check them!)

D = | row 1: 2 , -1 , 6 row 2: -3 , 4 , -5 row 3: 8 , -7 , -9 | = -141

For a 3 x 3, we have 3 more determinants to find:

, and

... Then we'll have

and

and

1 2 3

of 3

Cramer's Rule for 3x3's