## anonymous one year ago Medal and fan! which product represents the solution to the system? 3x+4y=-2 2x+5y=6

1. anonymous

apply matrices. $\left[\begin{matrix}3 & 4 \\ 2 & 5\end{matrix}\right]\left(\begin{matrix}x \\ y\end{matrix}\right)=\left(\begin{matrix}-2 \\ 6\end{matrix}\right)$

2. anonymous

I am sure you can follow the rules of matrices to find the solution of x and y now from the previous post

3. anonymous

4. anonymous

5. anonymous

try calculating the inverse of the matrix again

6. anonymous

??

7. anonymous

$\left[\begin{matrix}3 & 4 \\ 2 & 5\end{matrix}\right]\left(\begin{matrix}x \\ y\end{matrix}\right)=\left(\begin{matrix}-2 \\ 6\end{matrix}\right)$ $\left(\begin{matrix}x \\ y\end{matrix}\right)=\left[\begin{matrix}3 & 4 \\ 2 & 5\end{matrix}\right]^{-1}\left(\begin{matrix}-2 \\ 6\end{matrix}\right)$

8. anonymous

remember the inverse of a matrix for a 2x2 matrix $A=\left[\begin{matrix}a & b \\ c & d\end{matrix}\right]$ then $A ^{-1}=\frac{ 1 }{ ad-bc }\left[\begin{matrix}d & -b \\ -c & a\end{matrix}\right]$

9. anonymous

feel free to fan me so you can ask me for help straight away when you need it :)