Question

alguém pode me ajudar como faço essa matrizes pra achar o valor de x e y

Answer 1

Explicação passo-a-passo:

$A=\left[\begin{array}{ccc}1&2\\-1&6\\\end{array}\right]$     ;     $B=\left[\begin{array}{ccc}-3&8\\11&-12\\\end{array}\right]$     ;     $C=\left[\begin{array}{ccc}y&9\\1&x\\\end{array}\right]$

A · C = B

$\left[\begin{array}{ccc}1&2\\-1&6\\\end{array}\right].\left[\begin{array}{ccc}y&9\\1&x\\\end{array}\right]=\left[\begin{array}{ccc}-3&8\\11&-12\\\end{array}\right]$

$\left[\begin{array}{ccc}1.y+2.1&1.9+2.x\\-1.y+6.1&-1.9+6.x\\\end{array}\right]=\left[\begin{array}{ccc}-3&8\\11&-12\\\end{array}\right]$

$\left[\begin{array}{ccc}y+2&9+2x\\-y+6&-9+6x\\\end{array}\right]=\left[\begin{array}{ccc}-3&8\\11&-12\\\end{array}\right]$

Cálculo do y:

    usando y + 2

         y + 2 = -3 → y = -5

    usando -y + 6

         -y + 6 = 11 → -y = 5  →  y = -5

Cálculo do x

    usando 9 + 2x

         9 + 2x = 8 → 2x = -1 → $x=-\frac{1}{2}$

    usando -9 + 6x

         -9 + 6x = -12 → 6x = -3 → $x=-\frac{3}{6}$  →  $x=-\frac{1}{2}$

Portanto,  $x=-\frac{1}{2}$   e   $y=-5$