tolong ya kakak, tugasnya dateline ni

A - kI
=[tex] \left[\begin{array}{ccc}2&4\\3&1\\\end{array}\right] [/tex] - k[tex] \left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right] [/tex]
=[tex] \left[\begin{array}{ccc}2&4\\3&1\\\end{array}\right] [/tex] - [tex] \left[\begin{array}{ccc}k&0\\0&k\\\end{array}\right] [/tex]
=[tex] \left[\begin{array}{ccc}2-k&0\\3&1-k\\\end{array}\right] [/tex]

|A-kI| = (2 - k)(1- k ) - (4.3)
0 =2 - 2k - k + k² -12
0 = k² - 3k -10
0 = (k - 5)(k + 2)
k = 5 & k = -2