# Math Help - Matrice

1. ## Matrice

Hello i did not get this part on this example how they did this!matte3.bmp

2. ## Re: Matrice

Originally Posted by Petrus
Hello i did not get this part on this example how they did this!matte3.bmp
Multiply both sides by 9. See what happens.

3. ## Re: Matrice

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

4. ## Re: Matrice

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.

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