Solve the system by the substitution or the addition method.
-$\left\{ \begin{array} { l }
3 x + y = 4 \
4 x + 3 y = - 3
\end{array} \right.$
A)(3, -5)
B)(12, 3)
C)(9, -6)
D)(5, 3)

Question

Solve the system by the substitution or the addition method.
-$\left\{ \begin{array} { l } 
3 x + y = 4 \
4 x + 3 y = - 3
\end{array} \right.$
A)(3, -5)
B)(12, 3)
C)(9, -6)
D)(5, 3)

Quizplus · Accepted Answer

To solve the system, we can use the substitution method. First, solve the first equation for $y$: $y = 4 - 3x$. Then substitute this expression for $y$ in the second equation: $4x + 3(4 - 3x) = -3$. Simplifying gives $4x + 12 - 9x = -3$, which simplifies further to $-5x = -15$, so $x = 3$. Substituting $x = 3$ back into the first equation gives $3(3) + y = 4$, so $9 + y = 4$, and $y = -5$. Therefore, the solution is $x = 3$, $y = -5$, which corresponds to choice A.

Solve the System by the Substitution or the Addition Method {3x+y=44x+3y=−3\left\{ \begin{array} { l } 3 x + y = 4 \\4 x + 3 y = - 3\end{array} \right.{3x+y=44x+3y=−3​

Solve the System by the Substitution or the Addition Method $\left\{ \begin{array} { l } 3 x + y = 4 \\4 x + 3 y = - 3\end{array} \right.$