Solve the system of equations by using the inverse of the coefficient matrix if it exists and by the echelon method if the inverse doesn't exist.
-$$
\begin{array}{l}
3 x+y=15 \
2 x+4 y=0
\end{array}
$$
A) $ (-3,-6) $
B) $ (6,-3) $
C) $ (-3,6) $
D) No inverse, no solution for system

Question

Quizplus · Accepted Answer

The system of equations can be solved using the inverse of the coefficient matrix. The coefficient matrix is $\begin{pmatrix} 3 & 1 \ 2 & 4 \end{pmatrix}$, and its inverse exists. By calculating the inverse and applying it to the constants (15, 0), we find the solution $ (6, -3) $.

Solve the System of Equations by Using the Inverse of the Coefficient