disp('the augmented matrix is')
a=[1 0 -3 8;2 2 9 7;0 1 5 -2]
disp(a)
disp('R2=R2-2*R1')
a(2,:)=a(2,:)-2*a(1,:)
disp(a)
disp('interchange R2 and R3')
a([2,3],:)=a([3,2],:)
disp(a)
disp('R3=R3-2*R2')
a(3,:)=a(3,:)-2*a(2,:)
disp(a)
disp('R3=(1/5)*R3')
a(3,:)=(1/5)*a(3,:)
disp(a)
disp('R2=R2-5*R3 and R1=R1+3*R3')
a(2,:)=a(2,:)-5*a(3,:)
a(1,:)=a(1,:)+3*a(3,:)
disp(a)
s=[a(1,4);a(2,4);a(3,4)]
disp('solution is')
disp(s)