% data for Exercise Set 1.1
  
ex = input('Exercise number (1-4,7-18,29-32,34)? '); 

if ex==1
   M = [1 5 7;-2 -7 -5]
elseif ex==2
   M = [2 4 -4;5 7 11]
elseif ex==3
   M = [1 5 7;1 -2 -2]
elseif ex==4
   M = [1 -5 1; 3 -7 5]
elseif ex==7
   M = [1 7 3 -4; 0 1 -1 3;0 0 0 1;0 0 1 -2]
elseif ex==8
   M = [1 -4 9 0;0 1 7 0;0 0 2 0]
elseif ex==9
   M = [1 -1 0 0 -4;0 1 -3 0 -7;0 0 1 -3 -1;0 0 0 2 4]
elseif ex==10
   M = [1 -2 0 3 -2;0 1 0 -4 7;0 0 1 0 6;0 0 0 1 -3]
elseif ex==11
   M = [0 1 4 -5;1 3 5 -2;3 7 7 6]
elseif ex==12
   M = [1 -3 4 -4;3 -7 7 -8;-4 6 -1 7]
elseif ex==13 
   M = [1 0 -3 8;2 2 9 7;0 1 5 -2]  
elseif ex==14 
   M = [1 -3 0 5;-1 1 5 2;0 1 1 0]   
elseif ex==15   
   M = [1 0 3 0 2;0 1 0 -3 3;0 -2 3 2 1;3 0 0 7 -5]   
elseif ex==16 
   M = [1 0 0 -2 -3;0 2 2 0 0;0 0 1 3 1;-2 3 2 1 5]
elseif ex==17 
   M = [1 -4 1;2 -1 -3;-1 -3 4]  
elseif ex==18 
   M = [1 2 1 4;0 1 -1 1;1 3 0 0] 
elseif ex==29 
   M1 = [0 -2 5;1 4 -7;3 -1 6], M2 = [1 4 -7;0 -2 5;3 -1 6]
elseif ex==30
   M1 = [1 3 -4;0 -2 6;0 -5 9], M2 = [1 3 -4;0 1 -3;0 -5 9] 
elseif ex==31
   M1 = [1 -2 1 0;0 5 -2 8;4 -1 3 -6], M2 = [1 -2 1 0;0 5 -2 8;0 7 -1 -6]
elseif ex==32
   M1 = [1 2 -5 0;0 1 -3 -2;0 -3 9 5], M2 = [1 2 -5 0;0 1 -3 -2;0 0 0 -1]
elseif ex==34
   M = [4 -1 0 -1 30;-1 4 -1 0 60;0 -1 4 -1 70;-1 0 -1 4 40]
else 
   disp ('No data for this exercise in Section 1.1.')
end