Question

How do you solve 4x 5y = -7 and 3x - 6y = 24 using matrices?

Answer 1

Aw yis

take the coefients and put them in rows


$\left[\begin{array}{ccc}4&5&|-7\\3&-6&|24\end{array}\right]$
divide 2nd row by 3
$\left[\begin{array}{ccc}4&5&|-7\\1&-2&|8\end{array}\right]$
multiply 2nd row by -4 and add to top one
$\left[\begin{array}{ccc}0&13&|-39\\1&-2&|8\end{array}\right]$
divide top row by 13
$\left[\begin{array}{ccc}0&1&|-3\\1&-2&|8\end{array}\right]$
multiply top row by 2 and add to bottom row
$\left[\begin{array}{ccc}0&1&|-3\\1&0&|2\end{array}\right]$

x=2
y=-3