Question

ajutați ma va rog frumoss​

Answer 1

Răspuns:

Explicație pas cu pas:

$A=\left[\begin{array}{ccc}-1&2\\4&-3\end{array}\right] ; B=\left[\begin{array}{ccc}2&7\\-1&-4\end{array}\right]$$A+B=\left[\begin{array}{ccc}-1+2&2+7\\4+(-1)&-3+(-4)\end{array}\right]=\left[\begin{array}{ccc}1&9\\3&-7\end{array}\right]$$A-B=\left[\begin{array}{ccc}-1-2&2-7\\4-(-1)&-3-(-4)\end{array}\right]=\left[\begin{array}{ccc}-3&-5\\5&1\end{array}\right]$$2A+B=\left[\begin{array}{ccc}2*(-1)+2&2*2+7\\2*4+(-1)&2*(-3)+(-4)\end{array}\right]=\left[\begin{array}{ccc}0&11\\7&-10\end{array}\right]$$A*B=\left[\begin{array}{ccc}-1&2\\4&-3\end{array}\right]*\left[\begin{array}{ccc}2&7\\-1&-4\end{array}\right]=\left[\begin{array}{ccc}(-1)*2+2*(-1)&(-1)*7+2*(-4)\\4*2+(-3)*(-1)&4*7+(-3)*(-4)\end{array}\right]=\left[\begin{array}{ccc}-4&-15\\11&40\end{array}\right]$$detA=(-1)*(-3)-2*4=3-8=-5$