a) Suppose that B is the column vectorand A is an m × n matrix. View A as the row of colum...

a) Suppose that B is the column vector

and A is an m × n matrix. View A as the row of column vectors

where A1, A2 …, An are the columns of A. Show that

AB – b1A1 + b2A2 + … + bnAn.

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b) Use the result of part (a) to find AB for