Question

Dada as matrizes A= | 3 1 |     e B = | x+y     x-y| , determine x e y para que A=B 
                                      | 4 -2|               | 1        -2 |    

Answer 1

Oi Bianca,

se as matrizes são iguais:

$A=B~\to~ \left(\begin{array}{ccc}3&~~1\\4&-2\\\end{array}\right)= \left(\begin{array}{ccc}x+y&x-y\\1&-2\\\end{array}\right)\\\\\\ +\begin{cases}x+y=3\\ x-y=1\end{cases}\\ ~~~~~~~-----\\ ~~~~~~2x~~~~=4\\\\ ~~~~~~~x= \dfrac{4}{2}\\\\ ~~~~~~~x=2\\\\\\ x+y=3\\ 2+y=3\\ y=3-2\\ y=1\\\\\\ Portanto,~x~vale~2~e~y~vale~1$

Tenha ótimos estudos ;D