2.1     b) Inverse[{{2,-1},{3,2}}]
	c) Inverse[{{1,4},{2,8}}]
        d) Inverse[{{0,1,2},{1,0,1},{-2,3,0}}]
        e) Inverse[{{2,4,0},{3,4,-2},{-1,1,2}}]
        f) Inverse[{{0,1,1,1},{-1,0,1,1},{-1,-1,0,1},{-1,-1,-1,0}}]
	
2.2     a) Inverse[{{2,1},{3,2}}].{{1,-2},{0,3}}
        b) {{-2,1},{1,0}}.Inverse[{{1,2},{3,7}}]
        c) Inverse[{{1,1},{1,1}}].{{0,0},{0,0}}
        d) {{3,0,3}}.Inverse[{{1,2,1},{0,1,0},{1,2,-2}}]
        e) Inverse[{{1,0},{-3,1}}].{{1,0},{0,2}}.Inverse[{{1,0},{1,1}}]

2.3     a) Determinant[{{2,2,2},{2,2,2},{2,2,2}}]
        b) Determinant[{{2,2,3},{4,4,6},{5,5,5}}]
        c) Determinant[{{2,3,5},{3,0,0},{5,0,0}}]
        d) Determinant[{{4,-5,8},{0,0,5},{0,3,-8}}]

2.4     a) Determinant[{{1,2,2},{17,35,34},{11,20,23}}]
        c) Determinant[{{0,0,0,-5},{0,-1,0,0},{0,0,1,2},{3,0,2,0}}]
        d) Determinant[{{1,1,3,4},{2,0,0,8},{3,0,0,2},{4,4,7,5}}]
        f) Determinant[{{3,-3,-5,8},{-3,2,4,-6},{2,-5,-7,5},{-4,3,5,-6}}]
        g) Determinant[{{3,-3,-2,-5},{2,5,4,6},{5,5,8,7},{4,4,5,6}}]

2.4     a) solve Determinant[{{1,2,3},{4,5,6},{7,8,x}}] = 0
        b) solve Determinant[{{x,1,2},{0,2,0},{3,4,x}}] = 0
        c) solve Determinant[{{x,1,1},{0,x,0},{1,1,x}}] = 0