diketahui persamaan matriks [tex] \left[\begin{array}{ccc}1&3\\2&5\end{array}\right] \left[\begin{array}{ccc}4&-3\\-1&2\end{array}\right] = \left[\begin{a

[tex] \left[\begin{array}{ccc}1.4+3.-1&1.-3+3.2\\2.4+5.-1&2.-3+5.2\end{array}\right] [/tex] = [tex] \left[\begin{array}{ccc}-1+2&x+y\\2y+1&3+1\end{array}\right] [/tex]
[tex] \left[\begin{array}{ccc}1&3\\3&4\end{array}\right] = \left[\begin{array}{ccc}1&x+y\\2y+1&4\end{array}\right][/tex]
=> 2y + 1 = 3                    => x + y = 3
           2y = 3 - 1                    x + 1 = 3
           2y = 2                               x = 3 - 1
             y = 1                               x = 2

maka x + y = 2 + 1 = 3

maaf jika salah. semoga membantu ^_^