Results 1 to 3 of 3

Math Help - Matrices

  1. #1
    Junior Member
    Joined
    Jan 2007
    Posts
    40

    Matrices

    I need help with this problem:

    Find 3A+B where A =
    {3 5}
    {-3 2}
    and B=
    {1 1}
    {3 3}

    Possible solutions are:
    {10 16}
    {12 9 }
    ---------
    {10 15}
    {-6 9 }
    ---------
    {10 16}
    {-6 9 }
    ---------
    {10 16}
    {-9 9 }
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by gretchen View Post
    I need help with this problem:

    Find 3A+B where A =
    {3 5}
    {-3 2}
    and B=
    {1 1}
    {3 3}

    Possible solutions are:
    {10 16}
    {12 9 }
    ---------
    {10 15}
    {-6 9 }
    ---------
    {10 16}
    {-6 9 }
    ---------
    {10 16}
    {-9 9 }

    Code:
     
    Find 3A+B where A = 
    { 3 5} 
    {-3 2} 
    and B=
    { 1 1}
    { 3 3}
     
    3 [ 3 5 ] + [ 1 1 ] = [ 3.3+1 3.5+1 ] = [ 10 16 ]
      [-3 2 ]   [ 3 3 ]   [-3.3+3 3.2+3 ]   [-6   9 ]
    RonL
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,662
    Thanks
    602
    Hello, gretchen!

    Didn't they teach you anything about Matrix Arithmetic?


    Find 3A+B where A \:= \:\begin{bmatrix}3 &  5 \\ \text{-}3 & 2\end{bmatrix} and B = \begin{bmatrix}1 & 1 \\ 3 & 3 \end{bmatrix}

    Possible solutions are: . \begin{bmatrix}10 & 16 \\ 12 & 9\end{bmatrix}\quad \begin{bmatrix}10 & 15 \\ \text{-}6 & 9\end{bmatrix}\quad\begin{bmatrix}10 & 16 \\\text{-}6 & 9\end{bmatrix}\quad\begin{bmatrix}10 & 16 \\ \text{-}9 &  9\end{bmatrix}

    3A + B \;=\;3\begin{bmatrix}3 & 5\\ \text{-}3&2\end{bmatrix} + \begin{bmatrix}1 & 1 \\ 3 & 3\end{bmatrix} \;=\;\begin{bmatrix}3(3) & 3(5) \\ 3(\text{-}3) & 3(2)\end{bmatrix} + \begin{bmatrix}1 & 1 \\ 3 & 3\end{bmatrix}

    . . . . . . = \;\begin{bmatrix}9 & 15 \\ -9 & 6\end{bmatrix} + \begin{bmatrix}1 & 1 \\ 3 & 3\end{bmatrix} \;= \;\begin{bmatrix}9 + 1 & 15 + 1 \\ \text{-}9 + 3 & 6 + 3\end{bmatrix}

    . . . . . . = \;\begin{bmatrix}10 & 16 \\ \text{-}6 & 9\end{bmatrix} . . . third answer choice

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: November 25th 2010, 06:34 PM
  2. Total matrices and Commutative matrices in GL(r,Zn)
    Posted in the Advanced Algebra Forum
    Replies: 8
    Last Post: August 16th 2010, 02:11 AM
  3. Matrices Help
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: October 24th 2009, 09:36 PM
  4. Matrices represented by Symmetric/Skew Symmetric Matrices
    Posted in the Advanced Algebra Forum
    Replies: 7
    Last Post: October 25th 2008, 05:06 PM
  5. matrices
    Posted in the Algebra Forum
    Replies: 2
    Last Post: November 13th 2007, 02:36 PM

Search Tags


/mathhelpforum @mathhelpforum