# Matrice

• Jan 7th 2013, 02:45 PM
Petrus
Matrice
Hello i did not get this part on this example how they did this!Attachment 26507
• Jan 7th 2013, 02:52 PM
Plato
Re: Matrice
Quote:

Originally Posted by Petrus
Hello i did not get this part on this example how they did this!Attachment 26507

Multiply both sides by 9. See what happens.
• Jan 7th 2013, 03:14 PM
Petrus
Re: Matrice
Quote:

Originally Posted by Plato
Multiply both sides by 9. See what happens.

so idk really what im doing wrong.. well i dont get it why all - gets + and + gets - i did not get it :S
• Jan 7th 2013, 03:32 PM
Plato
Re: Matrice
Quote:

Originally Posted by Petrus
so idk really what im doing wrong.. well i dont get it why all - gets + and + gets - i did not get it :S

Oh, come on. Do some thinking for yourself.

$\displaystyle \left( {\begin{array}{*{20}c} {9a} \\ {9b} \\ {9c} \\ \end{array} } \right) - \left( {\begin{array}{r} {8a - 4b - 8c} \\ { - 4a + 2b + 4c} \\ { - 8a + 4b + 8c} \\ \end{array} } \right) =~ ?$