## DribleDaVaca19 Group Title Which matrix equation can be used to solve the system? Will draw it. one year ago one year ago

1. DribleDaVaca19

|dw:1370965723891:dw|

2. amistre64

Ax = b x = A^(-1) b might be one of the options

3. amistre64

they was nice enough to give you a determinant of 1 ... how sweet

4. DribleDaVaca19

i have 4 answers

5. amistre64

the answers might help us determine a suitable soluton process

6. DribleDaVaca19

|dw:1370966096557:dw|

7. amistre64

ax + by = n cx + cy = m matrix A = a b c d vector b = n m so yeah, they are looking for an inverse setup

8. DribleDaVaca19

|dw:1370966191827:dw|

9. amistre64

do you recall how to find the inverse of a 2x2 matrix?

10. amistre64

the shorcut involves a swap and some negations, youll also need a determinant

11. DribleDaVaca19

never mind I found it out, thx anyways

12. amistre64

$\begin{pmatrix}a&b\\c&d\end{pmatrix}^{-1}=\begin{pmatrix}d/|A|&-b/|A|\\-c/|A|&a/|A|\end{pmatrix}$