Punctul a
[tex] \left[\begin{array}{ccc}1&1&1\\x&0&6\\y&2&8\end{array}\right]=0
0+2x+6y-(0+12+8x)=0
2x+6y-12-8x=0
-6x+6y-12=0 /(-1)
6x-6y+12=0 / :6
x-y+2=0
[/tex]
Punctul b
[tex]A= \frac{1}{2}*|delta| [/tex]
[tex]delta= \left[\begin{array}{ccc}1&1&1\\0&6&3\\2&8&5\end{array}\right] =
30+6+0-(12+24+0)=36-12-24=0[/tex]
[tex]A= \frac{1}{2}*|0|=0 [/tex]
Punctul c
[tex]\left[\begin{array}{ccc}1&1&1\\0&6&3\\2&8&5\end{array}\right] = 30+6+0-(12+24+0)=36-12-24=0[/tex]
Punctele M,N,P sunt coliniare