Seven hundred gallons of 91-octane gasoline is obtained by mixing 87-octane gasoline with 94-octane gasoline.Write a system of equations in which one equation represents the amount of final mixture required and the other represents the amounts of 87- and 94-octane gasolines in the final mixture.Let x and y represent the numbers of gallons of 87-octane and 94-octane gasolines, respectively.
A) $\left\{ \begin{array} { c }
x + y = 85 \
87 x + 94 y = 63,700
\end{array} \right.$
B) $\left\{ \begin{array} { c }
87 x + 94 y = 700 \
x + y = 85
\end{array} \right.$
C) $\left\{ \begin{array} { l }
x + y = 63,700 \
87 x + 94 y = 85
\end{array} \right.$
D) $\left\{ \begin{array} { c }
87 x + 94 y = 700 \
x + y = 63,700
\end{array} \right.$
E) $\left\{ \begin{array} { c }
x + y = 700 \
87 x + 94 y = 63,700
\end{array} \right.$

Question

Seven hundred gallons of 91-octane gasoline is obtained by mixing 87-octane gasoline with 94-octane gasoline.Write a system of equations in which one equation represents the amount of final mixture required and the other represents the amounts of 87- and 94-octane gasolines in the final mixture.Let x and y represent the numbers of gallons of 87-octane and 94-octane gasolines, respectively.  
A)  $\left\{ \begin{array} { c } 
x + y = 85 \
87 x + 94 y = 63,700
\end{array} \right.$
B)  $\left\{ \begin{array} { c } 
87 x + 94 y = 700 \
x + y = 85
\end{array} \right.$
C)  $\left\{ \begin{array} { l } 
x + y = 63,700 \
87 x + 94 y = 85
\end{array} \right.$
D)  $\left\{ \begin{array} { c } 
87 x + 94 y = 700 \
x + y = 63,700
\end{array} \right.$
E)  $\left\{ \begin{array} { c } 
x + y = 700 \
87 x + 94 y = 63,700
\end{array} \right.$

Quizplus · Accepted Answer

The first equation, $x + y = 700$, represents the total amount of the final mixture, which is 700 gallons. The second equation, $87x + 94y = 63,700$, represents the weighted average needed to achieve the 91-octane level in the final 700-gallon mixture.

Seven Hundred Gallons of 91-Octane Gasoline Is Obtained by Mixing {x+y=8587x+94y=63,700\left\{ \begin{array} { c } x + y = 85 \\87 x + 94 y = 63,700\end{array} \right.{x+y=8587x+94y=63,700​

Seven Hundred Gallons of 91-Octane Gasoline Is Obtained by Mixing $\left\{ \begin{array} { c } x + y = 85 \\87 x + 94 y = 63,700\end{array} \right.$