Question

Dadas as matrizes
A= 3 1
1 -2
e
B= x+ y x-y
1 -2
determine x e y para que seja A=B

Answer 1

$A\left[\begin{array}{ccc}3&1\\1&-2\\\end{array}\right] \\ B \left[\begin{array}{ccc}x+y&x-y\\1&-2\end{array}\right] \\ \\ \\ \left \{ {{x+y=3} \atop {x-y=1}} \right. \\ \\ 2x=4 \\ x= \frac{4}{2} \\ x=2 \\ \\ x+y=3 \\ 2+y=3 \\ y=3-2 \\ y=1$