How do you solve $5x + 3y = -8$ and $4x + 6y = 8$ using matrices?

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Answer 1 · 2018-06-27T09:12:07

The solution is $((x),(y))=((-4),(4))$

The equation in matrix form is

$AX=B$

where

The matrix $A=((5,3),(4,6))$

$X=((x),(y))$

and

$B=((-8),(8))$

The solution is

$X=A^-1B$

The inverse of $A$ is

$A^-1=1/|(5,3),(4,6)|((6,-3),(-4,5))$

$=1/18((6,-3),(-4,5))$

Therefore,

$X=1/18((6,-3),(-4,5))((-8),(8))$

$=1/18((-72),(72))$

$=((-4),(4))$

The solution is

$((x),(y))=((-4),(4))$

How do you solve 5x + 3y = -85x + 3y = -8 and 4x + 6y = 84x + 6y = 8 using matrices?