Va rog ajutați-mă !!!!

Răspuns:
a) 2; b) 1
Explicație pas cu pas:
a)
[tex]Aria = \frac{1}{2} \times |\left[\begin{array}{ccc}1&2&1\\2&-1&1\\0&1&1\end{array}\right]| = \\ = \frac{1}{2} \times | - 1 + 2 - 1 - 4| = \frac{1}{2} \times | - 4| \\ = \frac{1}{2} \times 4 = 2[/tex]
b)
[tex]Aria = \frac{1}{2} \times |\left[\begin{array}{ccc}-2&3&1\\2&0&1\\1&1&1\end{array}\right]| = \\ = \frac{1}{2} \times |3 + 2 - ( - 2) - 6| \\ = \frac{1}{2} \times |1| = \frac{1}{2} [/tex]