matrix operaions sums multiplications

If I have 2 matrices say

B size (100, 2)

A size (100, n)

How to conduct the following operation?

B(1,1) * A(:,1) + B(1,2) * A(:,2)

Then in another column

B(2,1) * A(:,1) + B(2,2) * A(:,2)

And so on , that is each row of B multiplied by A. with loops or without. Thanks

[Image Analyst]

When do columns 3 to n of A ever get involved in this calculation???

Answer 1

[Roger Stafford]

   C = A(:,1:2)*B.';

Answer 2

[Shoaibur Rahman]

It seems that A(:,3:end) are never used. If that is the case, then you can simply use a for loop:

for k = 1:size(B,1)
    out(:,k) = B(k,1)*A(:,1)+B(k,2)*A(:,2);
end