tolong dong nmr 2 sama 4

2. Kurang jelas, pertanyaannya [tex] A^{-1} [/tex] dan [tex] B^{-1} [/tex] ?
    jika iya : 
    [tex] A^{-1} = \frac{1}{2.4-1.3} \left[\begin{array}{ccc}4&-1\\-3&2\\\end{array}\right] [/tex]
                 = [tex] \frac{1}{5} \left[\begin{array}{ccc}4&-1\\-3&2\\\end{array}\right] [/tex]
                 = [tex] \left[\begin{array}{ccc}4/5&-1/5\\-3/5&2/5\\\end{array}\right] [/tex]
  [tex] B^{-1} = \frac{1}{2.9-8.1} \left[\begin{array}{ccc}9&-8\\-1&2\\\end{array}\right] [/tex]
                   = [tex] \frac{1}{10} \left[\begin{array}{ccc}9&-8\\-1&2\\\end{array}\right] [/tex]
                   = [tex] \left[\begin{array}{ccc}9/10&-4/5\\-1/10&1/5\\\end{array}\right] [/tex]


4.  X. A = B
        X = B. [tex] A^{-1} [/tex]
           = [tex] \left[\begin{array}{ccc}1&0\\1&3\\\end{array}\right] [/tex]. [tex] \frac{1}{5.2-3.3} \left[\begin{array}{ccc}2&-3\\-3&5\\\end{array}\right] [/tex]
                   = [tex] \left[\begin{array}{ccc}(1)(2)+(0)(-3)&(1)(-3)+(0)(5)\\(1)(2)+(3)(-3)&(1)(-3)+(3)(5)\\\end{array}\right] = \left[\begin{array}{ccc}2&-3\\-7&12\\\end{array}\right] [/tex]