Question

Determine o valor de x e y utilizando a regra de Cramer 2x-y=5 x+y=1

Answer 1

$\large{\underbrace{Regra~de~Cramer}}$

$\,$

2x-y= 5

x+y= 1

$\,$

$\begin{Vmatrix}</p><p>&+2&-1&\\</p><p>&+1&+1&\\</p><p>\end{Vmatrix}$

$\,$

D=1.(2)-1.(-1)

$\,$

D=2+1

$\,$

D=3

$\,$

$\begin{Vmatrix}</p><p>&+5&-1&\\</p><p>&+1&+1&\\</p><p>\end{Vmatrix}$

$\,$

Dx=1.(5)-1.(-1)

$\,$

Dx=5+1

$\,$

Dx=6

$\,$

$\begin{Vmatrix}</p><p>&+2&5&\\</p><p>&+1&1&\\</p><p>\end{Vmatrix}$

$\,$

Dy=1.(2)-5.(1)

$\,$

Dy=2-5

$\,$

Dy=-3

$\,$

Encontrando os valores x e y:

$\,$

X=Dx/D=6/3= 2

$\,$

Y=Dy/D=-3/3=-1

$\,$

Os valores de x e y serão: 2 e -1