How do tell Matlab to multiply a single array with one column of a matrix?

I have a one array which I need to multiply with a column of matrix. Based on my code below (After the ...%Call Substitute...line) Matlab takes the matrix as whole and thus dimensions wont match with those of the array. Any way I can go around this? This code is for solving a linear system with matrices A and B given...

clc
clear all
format long e

A = [2 1 3;2 6 8;6 8 18];
B = [1;3;5];

n = size(A);
tol = 1e-20;
er = 0;

%Call Gauss
for i=1:n
    s(i)=abs(A(i,1));
    for j=2:n
        if abs(A(i,j))>s(i)
            s(i)=abs(A(i,j));
        end
    end
end

%Call Eliminate
for k=1:n-1
    %Call Pivot
    p=k;
    big=abs(A(k,k)/s(k));
    for ii=k+1:n
        dummy=abs(A(ii,k)/s(ii));
        if dummy>big
            big=dummy;
            p=ii;
        end
    end
    if p~=k
        for jj=k:n
            dummy=A(p,jj);
            A(p,jj)=A(k,jj);
            A(k,jj)=dummy;
        end
        dummy=B(p);
        B(p)=B(k);
        B(k)=dummy;
        dummy=s(p);
        s(p)=s(k);
        s(k)=dummy;
    end

      %Back to Eliminate
      if abs(A(k,k)/s(k))<tol
          er=-1;
          exit for loop
      end
      for i=k+1:n
          factor=A(i,k)/A(k,k);
          for j=k+1:n
              A(i,j)=A(i,j)-factor*A(k,j);
          end
          B(i)=B(i)-factor*B(k);
      end
  end

if abs(A(n,n)/s(n))<tol
    er=-1;
end

if er~=-1

%Call Substitute
X(n)=B(n)/A(n,n)
for i=n-1:-1:1
    sum=0;
    for j=i+1:n
        sum=sum+A(i,j)*X(j);
    end
    X(n)=(B(n)-sum)/A(n,n)
end
end

Here is the what Matlab tells me:

Error using  / 
Matrix dimensions must agree.

Error in GaussEliminationwithPivoting (line 69)
X(n)=B(n)/A(n,n)

Answer 1

[Sean de Wolski]

Not sure what you want, but it sounds like you'll either want element by element division, i.e:

B(n)./A(n,n)

Or bsxfun to do the scalar expansion:

bsxfun(@rdivide,B(n),A(n,n));