有下面程序每一步代表什么含义及运算结果

Dim a(3,3)
b=Array(5,-10,3)
a(1,1)=8;a(1,2)=-2;a(2,2)=4;a(2,3)=-3;a(3,3)=3
FOr i=2 T0 3
a(i,i)=a(i,i)-a(i-1,1)^2/a(i-1,i-1)
b(i)=b(i)-b(i-1)*a(i-1,1)/a(i-1,i-1)
Next i
b(3)=b(3)/a(3,3)
For j=2 To 1
b(j)=(b(j)*b(j+1)^a(j,j+1))/a(i,i)
Next j
For k=1 To 3
Print "x";k;"y" b(k)
Next k