A local grocery store makes a 6-pound mixture of trail mix. The trail mix contains raisins, sunflower seeds, and chocolate-covered peanuts. The raisins cost $3 per pound, the sunflower seeds cost $1 per pound, and the chocolate-covered peanuts cost $1.50 per pound. The mixture calls for twice as many raisins as sunflower seeds. The total cost of the mixture is $11.50. Write a system of equations for the situation and solve for the amount of each item in the trail mix.

The mass of sunflower seeds in the mixture is 1-pound

The mass of chocolate-covered peanuts in the mixture is 3-pounds

The mass of raisins in the mixture is 2-pounds

Step-by-step explanation:

The given parameters are;

The cost per pound of raisins = $3

The cost per pound of sunflower seeds = $1

The cost per pound of chocolate-covered peanuts = $1.50

The mass of raisings in the mixture = 2 × The mass of sunflower seeds in the mixture

The total cost of the mixture = $11.50

The mass of the mixture = 6-pounds

Let x represent the mass of sunflower seeds in the mixture, and y represents the mass of chocolate-covered peanuts in the mixture, we have;

The mass of raisins in the mixture = 2 × x

The system of equation are;

2·x + x + y = 6...(1)

2·x × 3 + x × 1 + y × 1.5 = 11.50...(2)

Simplifying the above two equations give;

For equation (1), we have;

3·x + y = 6...(1)

For equation (2), we have;

7·x + 1.5·y = 11.50...(2)

Making y the subject of both formulas, gives;

For equation (1), we have;

y = 6 - 3·x

For equation (2), we have;

y = 11.50/1.5 - 7/1.5·x

Equating both equations of y, to find the common solution as follows;

6 - 3·x = 11.50/1.5 - 7/1.5·x

7/1.5·x  - 3·x = 11.50/1.5 - 6

14/3·x  - 3·x = 23/3 - 6

5/3·x = 5/3

x = 3/5 × 5/3 = 1

x = 1

The mass of sunflower seeds in the mixture = x = 1-pound

y = 6 - 3·x =  6 - 3 × 1 = 3

y = 3

-The mass of chocolate-covered peanuts in the mixture = y = 3-pounds

The mass of raisins in the mixture = 2 × x = 2 × 1 = 2-pounds.

21

step-by-step explanation:

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81