Explicație pas cu pas:
[tex]A_{1} = \left(\begin{array}{ccc} {2}^{1} &2 \cdot 1\\-1&0\end{array}\right)[/tex]
[tex]A_{2} = \left(\begin{array}{ccc} {2}^{2} &2 \cdot 2\\-1&0\end{array}\right)[/tex]
...
[tex]A_{n} = \left(\begin{array}{ccc} {2}^{n} &2 \cdot n\\-1&0\end{array}\right)[/tex]
=>
[tex]B = \left(\begin{array}{ccc} {2}^{1} + {2}^{2} + ... + {2}^{n} &2 \cdot (1 + 2 + ... + n)\\(-1) + (- 1) + ... + (- 1)&0\end{array}\right) = \\ = \left(\begin{array}{ccc} 2({2}^{n} - 1) &2 \cdot \frac{n(n + 1)}{2} \\-1 \cdot n&0\end{array}\right) = \left(\begin{array}{ccc} 2({2}^{n} - 1) &n(n + 1) \\-n&0\end{array}\right)[/tex]
