How many pounds of peanuts selling for $5 per pound should be mixed with cashews selling for $8 per pound to obtain 40 pounds of mixed nuts selling for $7 per pound? Write a system of two equations in two unknowns that would model the situation. Let x = number of pounds of peanuts and y = number of pounds of cashews.
A) $\left\{ \begin{array} { l }
x + y = 40 \
5 x + 8 y = 40
\end{array} \right.$
B) $\left\{ \begin{array} { l }
x + y = 40 \
5 x + 8 y = 280
\end{array} \right.$
C) $\left\{ \begin{array} { l }
x + y = 280 \
5 x + 8 y = 40
\end{array} \right.$
D) $\left\{ \begin{array} { l }
x + 40 = y \
5 x + 8 y = 280
\end{array} \right.$

Question

How many pounds of peanuts selling for $5 per pound should be mixed with cashews selling for $8 per pound to obtain 40 pounds of mixed nuts selling for $7 per pound? Write a system of two equations in two unknowns that would model the situation. Let x = number of pounds of peanuts and y = number of pounds of cashews.
A) $\left\{ \begin{array} { l } 
x + y = 40 \
5 x + 8 y = 40
\end{array} \right.$
B) $\left\{ \begin{array} { l } 
x + y = 40 \
5 x + 8 y = 280
\end{array} \right.$
C) $\left\{ \begin{array} { l } 
x + y = 280 \
5 x + 8 y = 40
\end{array} \right.$
D) $\left\{ \begin{array} { l } 
x + 40 = y \
5 x + 8 y = 280
\end{array} \right.$

Quizplus · Accepted Answer

We are looking for the number of pounds of peanuts (x) and cashews (y) needed to obtain 40 pounds of mixed nuts selling for $7 per pound. The first equation should state that the total number of pounds is 40: x + y = 40. The second equation should represent the total cost of the mix, which is the sum of the cost of the peanuts and the cost of the cashews. We know that peanuts are selling for $5 per pound and cashews are selling for $8 per pound, so the equation for the total cost is 5x + 8y = 7(40) or 5x + 8y = 280. The correct system of equations is therefore: 
$\left\{ \begin{array} { l } 
x + y = 40 \
5 x + 8 y = 280
\end{array} \right.$

How Many Pounds of Peanuts Selling for $5 Per Pound {x+y=405x+8y=40\left\{ \begin{array} { l } x + y = 40 \\5 x + 8 y = 40\end{array} \right.{x+y=405x+8y=40​

How Many Pounds of Peanuts Selling for $5 Per Pound $\left\{ \begin{array} { l } x + y = 40 \\5 x + 8 y = 40\end{array} \right.$