mohon jawabin soal no 20. mohon bantuannya. jawabnya pakai cara ya.. besuk udah harus d kumpul nih mohon bantuannya

semoga bermanfaat ya
maaf jika ada kesalahan

jawab

gunakan invers matriks

[tex] X\,=\,\left[\begin{array}{ccc}-3&-7\\2&5\end{array}\right]^{-1} \left[\begin{array}{ccc}2&-7\\-2&5\end{array}\right] [/tex]

[tex]X\,=\, \frac{1}{-3(5)-2(-7)} \left[\begin{array}{ccc}5&7\\-2&-3\end{array}\right] \left[\begin{array}{ccc}2&-7\\-2&5\end{array}\right][/tex]

[tex]X\,=\, -1 \left[\begin{array}{ccc}-4&0\\2&-1\end{array}\right] = \left[\begin{array}{ccc}4&0\\-2&1\end{array}\right] [/tex]