Question

Resolva os sistemas pelo metodo de matrizes :

$\left \{ {{3x + 4y = -8 } \atop {x - 5y = 6 }} \right.$

Answer 1

Matriz Completa

$M_C=\left[\begin{array}{ccc}3&4\\1&-5\end{array}\right] \Rightarrow detM_C=-15-4=-19$

Matriz "x"

$M_X= \left[\begin{array}{ccc}3&-8\\1&6\end{array}\right] \rightarrow detM_x=18+8=24$

Matriz "y"

$M_y= \left[\begin{array}{ccc}-8&4\\6&-5\end{array}\right] \rightarrow detM_y=40-24=16$

calculando os valores de x e y

$x=\frac{M_x}{M_C}=\frac{24}{-19}=-\frac{24}{19}\\ \\ \\ y=\frac{M_y}{M_C}=\frac{16}{-19}=-\frac{16}{19}$