>> A=[1 1;2 4]
A =
1 1
2 4
>> b=[35;94]
b =
35
94
>> D=det(A)
D =
2
>> x=A\b
x =
23
12
>> AA=[A,b]
AA =
1 1 35
2 4 94
>> rref(A)
ans =
1 0
0 1
>> rref(AA)
ans =
1 0 23
0 1 12
>> AA(2,:)=AA(1,:)*(-2)+AA(2,:)
AA =
1 1 35
0 2 24
>> AA(2,:)=AA(2,:)*(1/2)
AA =
1 1 35
0 1 12
>> AA(1,:)=AA(2,:)*(-1)+AA(1,:)
AA =
1 0 23
0 1 12
>> A
A =
1 1
2 4
>> b
b =
35
94