SOLUTION: Multiply matrix {{{(matrix(3,2, 3,1, 3,2, 4,3))}}} by matrix {{{( matrix(2,3, 7,2,1, 6,8,-2))}}}

Algebra ->  Matrices-and-determiminant -> SOLUTION: Multiply matrix {{{(matrix(3,2, 3,1, 3,2, 4,3))}}} by matrix {{{( matrix(2,3, 7,2,1, 6,8,-2))}}}      Log On


   

Question 555189: Multiply matrix %28matrix%283%2C2%2C%0D%0A%0D%0A3%2C1%2C%0D%0A3%2C2%2C%0D%0A4%2C3%29%29 by matrix %28+matrix%282%2C3%2C%0D%0A%0D%0A7%2C2%2C1%2C%0D%0A6%2C8%2C-2%29%29
Answer by Edwin McCravy(20086) About Me  (Show Source):
You can put this solution on YOUR website!

Here is the formula for multiplying a "3 down by 2 across" matrix 
by a "2 down by 3 across" matrix.  The matrix you get when you 
multiply twn matrices gets its "down dimension" from the first
matrix and its "across dimension" from the second matrix: 

%28matrix%283%2C2%2C%0D%0A%0D%0Aa%2Cb%2C%0D%0Ac%2Cd%2C%0D%0Ae%2Cf%29%29·%28+matrix%282%2C3%2C%0D%0A%0D%0Ag%2Ch%2Ci%2C%0D%0Aj%2Ck%2Cl%29%29 = 

Use that formula and you'll get this answer, which is "3 down by 3 across":

%28matrix%283%2C2%2C%0D%0A%0D%0A3%2C1%2C%0D%0A3%2C2%2C%0D%0A4%2C3%29%29·%28+matrix%282%2C3%2C%0D%0A%0D%0A7%2C2%2C1%2C%0D%0A6%2C8%2C-2%29%29 = %28matrix%283%2C3%2C%0D%0A%0D%0A27%2C14%2C1%2C33%2C22%2C-1%2C46%2C32%2C-2%29%29

Edwin