Which function(s)are decreasing on the interval

For a certain commodity the supply equation is given by S = 2p + 5 At a price of $1, there is a demand for 19 units of the commo

slava [35]

Answer:

The demand equation is: D=-4p+23

Step-by-step explanation:

To get started, we should keep in mind that the market price (p=3) occurs when supply equals demand ,therefore when p=3

S=2(3)+5=11

Thus, when p=3 D=11 and, according to the problem when p=1 D=19.

We already know two points on the demand curve. Great!

The demand equation is linear, so it has form D=bp+c.

The variable b is the slope of the demand linear equation . It can be computed through the formula

$b=\frac{y2-y1}{x2-x1}$ . equation 1

Substituting the two points (3,11) and (1,19) on equation 1.

$b=\frac{19-11}{1-3} =\frac{8}{-2}$

b=-4

Now we can find the value of intercept of the demand equation c trough point-slope form y-y1=b(x-x1).

We can use any of the points. Let's take (3,11) and write in point-slope :

y-11=-4(x-3)

y=-4x+11+12

y=-4x+23

Rewrite the linear equation according our variables D and p

D=-4P+23

Finally we found the demand equation !

5 0

3 years ago

Suppose that a large mixing tank initially holds 100 gallons of water in which 50 pounds of salt have been dissolved. Another br

Serggg [28]

Answer:

dA/dt = 12 - 2A/(100 + t)

Step-by-step explanation:

The differential equation of this problem is;

dA/dt = R_in - R_out

Where;

R_in is the rate at which salt enters

R_out is the rate at which salt exits

R_in = (concentration of salt in inflow) × (input rate of brine)

We are given;

Concentration of salt in inflow = 4 lb/gal

Input rate of brine = 3 gal/min

Thus;

R_in = 4 × 3 = 12 lb/min

Due to the fact that solution is pumped out at a slower rate, thus it is accumulating at the rate of (3 - 2)gal/min = 1 gal/min

So, after t minutes, there will be (100 + t) gallons in the tank

Therefore;

R_out = (concentration of salt in outflow) × (output rate of brine)

R_out = [A(t)/(100 + t)]lb/gal × 2 gal/min

R_out = 2A(t)/(100 + t) lb/min

So, we substitute the values of R_in and R_out into the Differential equation to get;

dA/dt = 12 - 2A(t)/(100 + t)

Since we are to use A foe A(t), thus the Differential equation is now;

dA/dt = 12 - 2A/(100 + t)

5 0

3 years ago

A person selecting a bank does not need to consider whether the staff is friendly and helpful. True False

Nostrana [21]

False, A person would not want a bank where they could not depend on the staff and be able to come to them if they were having problems with the bank account

8 0

3 years ago

Read 2 more answers

Which of the following best describes how to solve<br> 2x+3 = 2x + 37

weeeeeb [17]

Answer: The first option.

Step-by-step explanation:

If you square you get $2x+3=2x+9$

x=0

8 0

3 years ago

Can someone help me with a quick Algebra question, Thanks! ;)

Viktor [21]

The answer is equal to (B). The solutions are x = -7.7 and x = -1.3.

3 0

3 years ago