Question

Помогите пожалуйста ​

Answer 1

Объяснение:

$1.\\A\left(\begin{array}{ccc}1&2\\-3&4\\\end{array}\right)\ \ \ \ \ B\left(\begin{array}{ccc}2&1\\0&-1\\\end{array}\right).\\a)\ C=2B-A.\\C=2*\left(\begin{array}{ccc}2&1\\0&-1\\\end{array}\right)-\left(\begin{array}{ccc}1&2\\-3&4\\\end{array}\right)=\left(\begin{array}{ccc}4&2\\0&-2\\\end{array}\right)-\left(\begin{array}{ccc}1&2\\-3&4\\\end{array}\right)=\left(\begin{array}{ccc}3&0\\3&-6\\\end{array}\right).$

$b)\ C=B*A.\\C=\left(\begin{array}{ccc}2&1\\0&-1\\\end{array}\right)*\left(\begin{array}{ccc}1&2\\-3&4\\\end{array}\right)=\left(\begin{array}{ccc}-1&8\\3&-4\\\end{array}\right).\\c_{11}=b_{11}*a_{11}+b_{12}*a_{21}=2*1+1*(-3)=2-3=-1.\\c_{12}=b_{11}*a_{12}+b_{12}*a_{22}=2*2+1*4=4+4=8.\\c_{21}=b_{21}*a_{11}+b_{22}*a_{21}=0*1+(-1)*(-3)=0+3=3.\\c_{22}=b_{21}*a_{12}+b_{22}*a_{22}=0*2+(-1)*4=0-4=-4.$

$c)\ detA=1*4-(-3*2)=4+6=10.$

$d)\ B=\left(\begin{array}{ccc}2&1\\0&-1\\\end{array}\right)\ \ \ \ \ \ B^T=\left(\begin{array}{ccc}2&0\\1&-1\\\end{array}\right).$