Solve the system by the substitution method.
-$$\left\{ \begin{array} { r }
5 x - 2 y = - 1 \
x + 4 y = 35
\end{array} \right.$$
A) $\{ ( 3,8 ) \}$
B) $\{ ( 3,9 ) \}$
C) $\{ ( x , y ) \mid x + 4 y = 35 \}$
D) $\varnothing$

Question

Solve the system by the substitution method.
-$$\left\{ \begin{array} { r } 
5 x - 2 y = - 1 \
x + 4 y = 35
\end{array} \right.$$
A) $\{ ( 3,8 ) \}$
B) $\{ ( 3,9 ) \}$
C) $\{ ( x , y ) \mid x + 4 y = 35 \}$
D) $\varnothing$

Quizplus · Accepted Answer

First, solve one of the equations for one variable in terms of the other. From the second equation, $x = 35 - 4y$. Substitute this expression for $x$ in the first equation: $5(35 - 4y) - 2y = -1$. Simplify and solve for $y$, then use the value of $y$ to find $x$. Solving gives $y = 8$ and $x = 3$, so the solution is $\{(3,8)\}$.

Solve the System by the Substitution Method {5x−2y=−1x+4y=35\left\{ \begin{array} { r } 5 x - 2 y = - 1 \\x + 4 y = 35\end{array} \right.{5x−2y=−1x+4y=35​

Solve the System by the Substitution Method $\left\{ \begin{array} { r } 5 x - 2 y = - 1 \\x + 4 y = 35\end{array} \right.$