Solve using matrices.
-$$\begin{array} { r }
x + 7 y = - 2 \
3 x + y = 34
\end{array}$$
A) $( 3,7 )$
B) $( 12 , - 2 )$
C) $( 7,12 )$
D) $( - 2,3 )$

Question

Solve using matrices.
-$$\begin{array} { r } 
x + 7 y = - 2 \
3 x + y = 34
\end{array}$$
A) $( 3,7 )$
B) $( 12 , - 2 )$
C) $( 7,12 )$
D) $( - 2,3 )$

Quizplus · Accepted Answer

To solve the system of equations using matrices, we can use the inverse of the coefficient matrix. The system is:$$x + 7y = -2$$$$3x + y = 34$$The coefficient matrix is $\begin{pmatrix} 1 & 7 \ 3 & 1 \end{pmatrix}$, and the constant matrix is $\begin{pmatrix} -2 \ 34 \end{pmatrix}$.First, find the inverse of the coefficient matrix, then multiply it by the constant matrix to find the values of $x$ and $y$.The inverse of the coefficient matrix is calculated, and then we multiply it by the constant matrix to get the solution $(x, y) = (12, -2)$.

Solve Using Matrices x+7y=−23x+y=34\begin{array} { r } x + 7 y = - 2 \\3 x + y = 34\end{array}x+7y=−23x+y=34​

Solve Using Matrices $\begin{array} { r } x + 7 y = - 2 \\3 x + y = 34\end{array}$