1.a) det A= 4-4=0
b)[tex] \left[\begin{array}{ccc}1&2\\2&4\\\end{array}\right] * \left[\begin{array}{ccc}1&2\\2&4\\\end{array}\right] = \left[\begin{array}{ccc}5&10\\10&20\\\end{array}\right] =5A[/tex]
C)[tex] \left[\begin{array}{ccc}1&2\\2&4\\\end{array}\right] + \left[\begin{array}{ccc}x&y\\y&-3\\\end{array}\right] =I2 \\ 1+x=1, x=0 \\ 2+y=0, y=-2[/tex]
2a)(-1)*1=-1+1-1=-1
b)x*y=xy+x+y-1+1=xy+x+y
c) x+1+x-3+x²-3x+x-3=4
x²=9
x1=3
x2=-3
