Express the column matrix b as a linear combination of the columns of A. (Use A1, A2, and A3 respectively for the columns of A.)

Question

A= [1 -1 2 ] B= [ -1

1 3 -3 9

Answer 1

What is A and what is B? What I see are just two vectors. A=(1,-1,2) and B=(-1,1,3,-3,9).