Subiectul al II-lea
a)detA=1*0-2*1=-2
b)A+B=AB+C
[tex] \left(\begin{array}{ccc}1&2\\1&0\\\end{array}\right) + \left(\begin{array}{ccc}b&b\\0&0\\\end{array}\right)= \left(\begin{array}{ccc}1&2\\1&0\\\end{array}\right) *\left(\begin{array}{ccc}b&b\\0&0\\\end{array}\right)+ \left(\begin{array}{ccc}1&0\\0&1\\\end{array}\right) \\ \left(\begin{array}{ccc}1+b&2+n\\1&0\\\end{array}\right) = \left(\begin{array}{ccc}b&b\\b&b\\\end{array}\right) + \left(\begin{array}{ccc}1&0\\0&1\\\end{array}\right) [/tex][tex]\left(\begin{array}
{ccc}1+b&2+b\\1&0\\\end{array}\right)= \left[\begin{array}{ccc}b+1&b\\\\b&b+1\end{array}\right] \\ \left \{ {{1+b=b+1} \atop {2+b=b}} \right. \left \\ \left \{ {{1=b} \atop {0=b+1}} \right. [/tex]
Si rezolvi sistemele
