Adam prepares a meal of shrimp and brown rice. it must contain exactly 6 g of fat and 10 mg of iron. each 5oz serving of shrimp contains 2 g fat and 5 mg iron. each 1 cup of brown rice contains 6 g fat and 7 mg iron. how many servings of shrimp and brown rice should be in the meal?

Adam needs 9/8 of a 5oz serving of shrimps (which equals to 5.625 oz) and 5/8 of a cup of brown rice (which is around 10 tablespoons).

Explanation:

You are given:

every serving of shrimp contains 2g of fat and 5mg of iron;

every serving of rice contains 6g of fat and 7mg of iron;

each meal should have 6g of total fat and 10mg of total iron.

You need to set a system of equation: let's call

s = quantity of shrimps

r = quantity of rice

The equation for the total fat will be: the quantity of fat in the serving of shrimps plus the quantity of fat in the serving of rice must be equal to 6g

2s + 6r = 6    (1)

Similarily:

the quantity of iron in the serving of shrimps plus the quantity of iron in the serving of rice must be equal to 10g

5s + 7r = 10     (2)

In order to solve the system, solve for s in equation (1):

s = (6-6r)/2 = 3 - 3r        (3)

Substitute in equation (2):

5(3 - 3r) + 7r = 10

and solve for r:

15 - 15r + 7r = 10

8r = 5

r = 5/8

Substitute the value of r in equation (3):

s = 3 - 3×5/8 = 9/8

Therefore Adam would need 9/8 of a 5oz serving of shrimps and 5/8 of a 1 cup of brown rice for each meal.

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12

-8/2y-8=5/y+4-7y+8/y^2-16

we move all terms to the left:

-8/2y-8-(5/y+4-7y+8/y^2-16)=0

we can not solve this equation