## anonymous one year ago Question 38 of 165 Solve the system of linear equations below. 2x + y = 5 x + y = 4 x = 1, y = 3 x = 1, y = 5 x = 3, y = 1 x = 9, y = -5

1. anonymous

you can subtract the two equations, then the y term will disappear and then you can find x

2. anonymous

$\left[\begin{matrix}2 & 1 \\ 1 & 1\end{matrix}\right]\left[\begin{matrix}x \\ y\end{matrix}\right]=\left[\begin{matrix}5 \\ 4\end{matrix}\right]$$|A| = (2 \times 1) - (1 \times 1 ) = 1$$A ^{-1} = \left[\begin{matrix}1 & -1 \\ -1 & 2\end{matrix}\right]$$\left[\begin{matrix}1 & -1 \\ -1 & 2\end{matrix}\right]\left[\begin{matrix}5 \\ 4\end{matrix}\right]=\left[\begin{matrix}? \\ ?\end{matrix}\right]$

3. anonymous

so....its....

4. anonymous

do the matrix multiplication and find out :)

5. anonymous

and that is....

6. anonymous

answer isnt that important its how you get there

7. anonymous

noo im saying whats matrix multiplication

8. anonymous

x=1 y=5

9. anonymous

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10. anonymous

im on question 103 now so....