If you do width times length you will get 30. Good luck
The <u><em>correct answer</em></u> is:
d) People per hour, because the dependent quantity is the people
Explanation:
In this situation, the two quantities are people and hours. These are the two things in this problem we can count or measure.
The independent variable is the one that causes a change, while the dependent variable is the one that <em>gets</em> changed. In this situation, the number of people change every hour; this means the number of people <em>gets</em> changed, which makes it the dependent variable. This means that the independent variable must be time.
Since people is dependent and time is independent, "people per hour" would be the best form of this statement.
7x^2 + 3
7(4)^2 + 3
7(16) + 3
112 + 3
115.
Y = -4x - 5.....(0,?)...so we know x = 0, so sub in 0 for x and solve for y
y = -4(0) - 5
y = -5....so one point is (0,-5)
do the same for the other points and u get (1,-9) , (-1,-1)
y = -4x - 5.....slope is -4 and ur y int (where ur line crosses the y axes) is (0,-5).
to find the x int (where the line crosses the x axes), sub in 0 for y and solve for x.
0 = -4x - 5
4x = -5
x = -5/4.....or - 1 1/4(for graphing purposes)...x int is (-5/4,0)
so plot all ur points and connect the dots
============================
4x + 9y = 0...(-9,?)..so x = -9..so sub in -9 for x and solve for y
4(-9) + 9y = 0
-36 + 9y = 0
9y = 36
y = 36/9
y = 4...so ur point is (-9,4)
do the same for the others and ur points are : (0,0) , (9,-4)
4x + 9y = 0
9y = -4x....so ur slope is -4 and ur y int is (0,0)
ur x int is : (0,0)....so basically u have a line going through the origin (0,0)
plot all ur points and connect the dots
Answer:
(a) Amount of salt as a function of time

(b) The time at which the amount of salt in the tank reaches 50 lb is 23.5 minutes.
(c) The amount of salt when t approaches to +inf is 100 lb.
Step-by-step explanation:
The rate of change of the amount of salt can be written as

Then we can rearrange and integrate

Then we have the model of A(t) like

(b) The time at which the amount of salt reaches 50 lb is

(c) When t approaches to +infinit, the term e^(-0.02t) approaches to zero, so the amount of salt in the solution approaches to 100 lb.