Consider the following system: $$\left\{ \begin{array} { c }
7 x + y = 54 \
y = - 7 x - 18
\end{array} \right.$$ Substitute $- 7 x - 18$ for y in the first equation. How many variables does the resulting equation contain?
A)1
B)0
C)2
D)4
E)none of the above

Question

Consider the following system: $$\left\{ \begin{array} { c } 
7 x + y = 54 \
y = - 7 x - 18
\end{array} \right.$$ Substitute $- 7 x - 18$ for y in the first equation. How many variables does the resulting equation contain?
A)1
B)0
C)2
D)4
E)none of the above

Quizplus · Accepted Answer

The Answer of Consider the following system: $$\left\{ \begin{array} { c } 
7 x + y = 54 \
y = - 7 x - 18
\end{array} \right.$$ Substitute $- 7 x - 18$ for y in the first equation. How many variables does the resulting equation contain?
A)1
B)0
C)2
D)4
E)none of the above

Consider the Following System {7x+y=54y=−7x−18\left\{ \begin{array} { c } 7 x + y = 54 \\y = - 7 x - 18\end{array} \right.{7x+y=54y=−7x−18​

Consider the Following System $\left\{ \begin{array} { c } 7 x + y = 54 \\y = - 7 x - 18\end{array} \right.$