Question

42 БАЛЛА!
РЕШИТЬ МЕТОДОМ КАМЕРА!!​

Answer 1

$\Delta =\left|\begin{array}{rrr}-3&5&2\\4&-7&5\\2&4&-3\end{array}\right|=-3(21-20)-5(-12-10)+2(16+14)=167\ne 0\\\\\\\Delta _1=\left|\begin{array}{rrr}20&5&2\\-13&-7&5\\20&4&-3\end{array}\right|=20(21-20)-5(39-100)+2(-52+140)=501$

$\Delta _2=\left|\begin{array}{rrr}-3&20&2\\4&-13&5\\2&20&-3\end{array}\right|=-3(39-100)-20(-12-10)+2(80+26)=835\\\\\\\Delta _3=\left|\begin{array}{rrr}-3&5&20\\4&-7&-13\\2&4&20\end{array}\right|=-3(-140+52)-5(80+26)+20(16+14)=334\\\\\\x=\frac{501}{167}=3\; ,\; \; y= \frac{835}{167}=5\; \; ,\; \; z=\frac{334}{167}=2\\\\Otvet:\; \; x=3\; ,\; y=5\; ,\; z=2\; .$