2.1	Inverse[{{1,4},{-4,1}}]

2.8	b) solve Determinant[{{k,1,2},{0,2,0},{3,4,k}}]=0

2.9	a) Inverse[{{0,1,2},{3,0,1},{-2,3,0}}]
	b) Inverse[{{1,1,1,1},{0,1,1,1},{0,0,1,1},{0,0,0,1}}]

2.10	e) Inverse[{{2,4,0},{3,4,-2},{-1,1,2}}]

2.13	a) LinearSolve[{{4,2,6},{1,-2,3},{1,-1,3}},{-3,-1,-3/2}]

2.14	b) {{-2,1},{1,0}}.Inverse[{{1,2},{3,7}}]
	e) Inverse[{{0,4,1},{-2,1,3},{2,4,9}}].{{4,6},{-3,7},{8,22}}
		
2.15	b) Inverse[{{2,-3,1},{4,-5,2},{5,-7,3}}].{{2,0,-2},{18,12,9},{23,15,11}}.Inverse[{{9,7,6},{1,1,2},{1,1,1}}]
	d) Inverse[{{1,2},{4,-1}}].{{2,0},{1,-1}}.Inverse[{{0,5},{1,1}}]