Question Number 112904 by mohammad17 last updated on 10/Sep/20
$${solve}\:{the}\:{equation}\:{y}+{x}=\mathrm{3},\:\mathrm{2}{y}+{x}=\mathrm{5}\:{by}\:{ussing}\:{matrixis}\:{method} \\ $$$${help}\:{me}\:{sir}\:{please}\:? \\ $$
Answered by bemath last updated on 10/Sep/20
$$\begin{pmatrix}{\mathrm{1}\:\:\:\mathrm{1}}\\{\mathrm{1}\:\:\:\mathrm{2}}\end{pmatrix}\begin{pmatrix}{\mathrm{x}}\\{\mathrm{y}}\end{pmatrix}=\begin{pmatrix}{\mathrm{3}}\\{\mathrm{5}}\end{pmatrix} \\ $$$$\begin{pmatrix}{\mathrm{x}}\\{\mathrm{y}}\end{pmatrix}=\begin{pmatrix}{\mathrm{1}\:\:\:\mathrm{1}}\\{\mathrm{1}\:\:\:\mathrm{2}}\end{pmatrix}^{−\mathrm{1}} \begin{pmatrix}{\mathrm{3}}\\{\mathrm{5}}\end{pmatrix} \\ $$$$\:\:\:\:\:\:\:\:=\:\frac{\mathrm{1}}{\mathrm{1}}\begin{pmatrix}{\mathrm{2}\:\:\:\:\:−\mathrm{1}}\\{−\mathrm{1}\:\:\:\:\mathrm{1}}\end{pmatrix}\begin{pmatrix}{\mathrm{3}}\\{\mathrm{5}}\end{pmatrix} \\ $$$$\:\:\:\:\:\:\:\:=\begin{pmatrix}{\:\:\:\:\mathrm{6}−\mathrm{5}}\\{−\mathrm{3}+\mathrm{5}}\end{pmatrix}=\begin{pmatrix}{\mathrm{1}}\\{\mathrm{2}}\end{pmatrix} \\ $$
Commented by mohammad17 last updated on 10/Sep/20
$${thank}\:{you}\:{sir} \\ $$