Complete the table below.

Number of pounds
Dollars per pound
Cost
​(in dollars)
x
18
  
18 x
y
  
6
  
6 y
90
  
10
  
900
​(Simplify your answers. Use integers or decimals for any numbers in the​ expression.)
Part 2
The person will need
  
enter your response here pounds of ​$18 coffee and
  
enter your response here pounds of ​$6 coffee.

1 answer

To complete the table, we need to fill in the cost for each entry:

Table Completion:

| Number of pounds | Dollars per pound | Cost (in dollars) | |------------------|-------------------|----------------------| | x | 18 | 18x | | y | 6 | 6y | | 90 | 10 | 900 |

Finding x and y:

Let's assume that the total amount of coffee (pounds) needed is 90 pounds, and the average cost given is $10 per pound.

To find how much of each type of coffee the person will need:

Let \( x \) be the pounds of $18 coffee and \( y \) be the pounds of $6 coffee. We have two conditions:

  1. The total weight of the coffee:
    \( x + y = 90 \)

  2. The total cost of the coffee:
    The average cost equation can be set up as:
    \[ \frac{(18x + 6y)}{90} = 10 \] Multiplying both sides by 90 gives: \[ 18x + 6y = 900 \]

Solving the equations:

From the first equation: \[ y = 90 - x \]

Substituting \( y \) in the second equation: \[ 18x + 6(90 - x) = 900 \]

Expanding: \[ 18x + 540 - 6x = 900 \] Combining like terms: \[ 12x + 540 = 900 \] Subtracting 540 from both sides: \[ 12x = 360 \] Dividing by 12: \[ x = 30 \]

Substituting back for \( y \): \[ y = 90 - 30 = 60 \]

Final Answers:

  • The person will need 30 pounds of $18 coffee.
  • The person will need 60 pounds of $6 coffee.

Filled Part 2:

  • 30 pounds of $18 coffee
  • 60 pounds of $6 coffee