Noah's Café sells special blends of coffee mixtures. Noah wants to create a 20-pound mixture with coffee that sells for $9.20 per pound and coffee that sells for $5.50 per pound. How many pounds of each mixture should he blend to create coffee that sells for $6.98 per pound?

Noah needs 8 pounds of the coffee that costs $9.20 per pound and 12 pounds of the coffee that costs $5.50 per pounds

Step-by-step explanation:

Let the number of pounds of the coffee that sells for 9.20 be x while the number of pounds of the coffee that sells for 5.5 be y.

From the question, we know he wants to make 20 pounds of coffee

Thus;

x + y = 20 •••••••••••(i)

Let’s now work with the values

For the $9.20 per pound coffee, the cost out of the total will be 9.20 * x = $9.20x

For the $5.5 per pound coffee, the cost out of the total be 5.5 * y = $5.5y

The total cost is 20 pounds at $6.98 per pound: that would be 20 * 6.98 = $139.6

Thus by adding the two costs together we have a total of $139.6

So we have our second equation;

9.2x + 5.5y = 139.6 •••••••(ii)

From i, y = 20 - x

Let’s substitute this in ii

9.2x + 5.5(20-x) = 139.6

9.2x + 110 -5.5x = 139.6

9.2x -5.5x = 139.6-110

3.7x = 29.6

x = 29.6/3.7

x = 8 pounds

Recall;

y = 20 - x

y = 20-8

y = 12 pounds

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below: