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Homework Help: Finding elementary matrices E1 and E2 such that: B = E1E2A, confused!

  1. Oct 30, 2005 #1
    Hello everyone, i've been searching in this book forever to find an example but no luck. My problem states:
    Find two Elementary matrices E1 and E2 such that [tex]B = E_2E_1A[/tex]
    A =
    2 3
    -1 8

    B =
    1 11
    3 -24

    Can someone explain to me what they want me to do?
    The books says:
    A -> E1A->E2E1A -> Ek .... E2E1A;
    Ei denote the elementary matrix corresponding to the ith row operation. and suppose that a series of k elementary row operations is applied to an arbitrary matrix A.

  2. jcsd
  3. Oct 31, 2005 #2


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    Science Advisor
    Homework Helper

    Staring at the matrices for a moment makes it clear that the two row operations they want are:

    (1) Add the second row to the first row.
    (2) Multiply the second row by -3.

    Can you write down these matrices?

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