From 1999 to 2000, the number of days of unhealthy air quality in Charlotte, North Carolina, dropped from 5 to 2. Find the percent of decrease in the number of days of unhealthy air.
A.
15%
B.
6%
C.
1.5%
D.
60%
Answer: it’s D which is 60%, hope it helps
The radius of a cylinder is increasing at a constant rate of 2 inches per minute. The volume remains a constant 440 cubic inches. At the instant when the radius of the cylinder is 44 inches, what is the rate of change of the height? The volume of a cylinder can be found with the equation V= [tex]\pi r^2h[/tex] Round your answer to three decimal places.
Answer:
The rate of change of the height is approximately [tex]-6.577\times 10^{-3}\,\frac{in}{min}[/tex].
Step-by-step explanation:
From Geometry we know that volume of cylinder ([tex]V[/tex]), measured in cubic inches, is expressed by:
[tex]V = \pi\cdot r^{2}\cdot h[/tex] (1)
Where:
[tex]r[/tex] - Radius, measured in inches.
[tex]h[/tex] - Height, measured in inches.
Given that volume remains constant, the expression for the rate of change of the height ([tex]\dot h[/tex]), measured in inches per minute, is:
[tex]2\pi\cdot r \cdot h \cdot \dot r + \pi \cdot r^{2}\cdot \dot h = 0[/tex]
[tex]2\cdot h\cdot \dot r + r\cdot \dot h = 0[/tex]
[tex]r\cdot \dot h = -2\cdot h \cdot \dot r[/tex]
[tex]\dot h = -\frac{2\cdot h\cdot \dot r}{r}[/tex]
[tex]\dot h = - \left(\frac{2\cdot \dot r}{r}\right)\cdot \left(\frac{V}{\pi\cdot r^{2}} \right)[/tex]
[tex]\dot h = -\frac{2\cdot \dot r \cdot V}{\pi\cdot r^{3}}[/tex] (2)
Where [tex]\dot r[/tex] is the rate of change of the radius, measured in inches per minute.
If we know that [tex]r = 44\,in[/tex], [tex]\dot r = 2\,\frac{in}{min}[/tex] and [tex]V = 440\,in^{3}[/tex], then the rate of change of the height is:
[tex]\dot h = - \frac{2\cdot \left(2\,\frac{in}{min} \right)\cdot \left(440\,in^{3}\right)}{\pi\cdot (44\,in)^{3}}[/tex]
[tex]\dot h \approx -6.577\times 10^{-3}\,\frac{in}{min}[/tex]
The rate of change of the height is approximately [tex]-6.577\times 10^{-3}\,\frac{in}{min}[/tex].
10, 6, 3, 10, 1
Mode ??
Median ??
Answer:
Median is 6 Mode is 10
Step-by-step explanation:
Median is the middle number when all the numbers are lined up in order.
Mode is the number that shows up most frequently.
Answer:
Mode: 10
Median: 6
Step-by-step explanation:
Mrs. Smith bought a used car. She paid $6,500 plus sales tax. The sales
tax was 7%. How much did she pay in sales tax?
Answer:
$450
Step-by-step explanation:
1.1. Which statement explains why the two systems of equations below have the
same solution?
A(6x + 8y = -10
2x - 5y = 12
B
8x + 3y = 2
12x + 16y = - 20
A. The first equation in B is the sum of the equations in A, while the other is obtained
by multiplying the second equation in A by 6.
B. The first equation in B is the sum of the equations in A, while the other is obtained
by multiplying the first equation in A by 2.
C. The equations in A are increased by 12 and -32 to get the equations in
D. The equations in A are multiplied by 2 and 4 to get the equations in B.
Answer:
Correct Answer is B. The first equation in B is the sum of the equations in A, while the other is obtained by multiplying the first equation in A by 2.
Step-by-step explanation:
As given,
A : 6x + 8y = -10 .......equation (1)
2x - 5y = 12 .......equation (2)
B : 8x + 3y = 2 .......equation (1)
12x + 16y = - 20 .......equation (1)
Correct Answer is B. The first equation in B is the sum of the equations in A, while the other is obtained by multiplying the first equation in A by 2.
Proof :
The first part says that ,
Sum of equation (1) of A and equation (2) of A = Equation (1) of B
Firstly , find the Sum of equation (1) of A and equation (2) of A
⇒6x + 8y + 2x - 5y = -10 + 12
⇒8x + 3y = 2
this is same as equation (1) of B
So, it satisfies the first part
The second part says that,
The equation (2) of B is obtained by multiplying the first equation in A by 2.
It means , if the equation (1) is multiplied by 2 = equation (2) of B
Firstly , if the equation (1) is multiplied by 2 , we get
2 ( 6x + 8y = -10 )
⇒ 2 ( 6x + 8y ) = 2 ( -10)
⇒ 12x + 16y = -20
this is same as equation (2) of B
So, it satisfies the second part.
Which equation could be used for the situation below?
Jenna earns $8 each week by completing chores. She already has $12 in her savings. How much will she have after 4 weeks?
y = 8x + 4
y = 8x
y = 8x + 12
Answer:
Option C is the correct answer.
Step-by-step explanation:
Per week earning = $8
Amount in savings = $12
y = Total amount
x = Number of weeks
y = 8x + 12
Where we can put x=4 to calculate earning of 4 weeks.
y = 8(4) + 12
y = 32 + 12 = $44
Therefore,
Option C is the correct answer.
I need answers to these.
Please answer this ASAP
Answer: 2x and y= 4+
Step-by-step explanation:
x = 2 times 2 and so on....
y = 4 plus 4 plus 4 etc....
Mrs.Giblin begins hiking at mile marker 25 on the Appalachian Trail and hikes 3 miles every hour. What is the slope?
Answer:
3 miles
Step-by-step explanation:
Slope is simply the change in position per unit rate. We could conclude that the steepness of the Applachian is the rate of change in position per unit time. Since the distance hiked on the Applachian is said to be 3 miles per hour, then we can conclude that the slope of the applachian is 3 miles
This is the change in miles / change in time.
Chang in miles = 3
Change in time = 1
Slope = 3/1
Slope = 3
Use multiplication to find the quotient. 5 / 1/4
Answer:
20
Step-by-step explanation:
5/ 1/4 --> 5 x 4 (flip the 1 and 4 in 1/4)
Describe how the graph of y= 2x + 7 is the same and
different from the graph of y=2x - 7.
Answer: the placement/ digest are the same but because on is positive and the other is negative, the answer will be different
Step-by-step explanation:
Answer:
different y-intercepts; same slopes
Step-by-step explanation:
if x=0, then y=7,-7
During second period, Bryant completed a grammar worksheet. He got 21 out of 75 questions
correct. What percentage did Bryant get correct?
It rained 6 days in the month of april. What percent of the month did it rain?
**there are 30 days in April**
Answer:
5% of the time or in a decimal it's 0.05
The number of pizzas y you need for a party is proportional to the number of people x attending the party. You will need 2 pizzas for 10 people.
a. Write an equation that represents the situation. (Remember y=mx)
b. Interpret the slope.
c. How many pizzas are needed for 25 people?
PLS HELP ASAP I DONT HAVE TIME FOR THIS, IT ALSO DETECTS IF ITS RIGHT IR WRONG
Answer:
a
Step-by-step explanation:
How many solutions does 3(x + 5) – 3 = 2(3x + 1) – 3x have? Show your work.
Answer: There are no solution
Step 1: Simplify both sides of the equation.
3(x+5)−3=2(3x+1)−3x
(3)(x)+(3)(5)+−3=(2)(3x)+(2)(1)+−3x(Distribute)
3x+15+−3=6x+2+−3x
(3x)+(15+−3)=(6x+−3x)+(2)(Combine Like Terms)
3x+12=3x+2
3x+12=3x+2
Step 2: Subtract 3x from both sides.
3x+12−3x=3x+2−3x
12=2
Step 3: Subtract 12 from both sides.
12−12=2−12
0=−10
After solving the equation, the value obtained for x is 0, which means that there is no solution for the equation.
What is an equation?Mathematical expressions with two algebraic symbols on either side of the equal (=) sign are called equations.
This relationship is illustrated by the left and right expressions being equal. The left-hand side equals the right-hand side is a basic, straightforward equation.
As per the given equation mentioned in the question,
3(x + 5) - 3 = 2(3x + 1) - 3x
Let's simplify the equation first,
3x + 15 - 3 = 6x + 2 - 3x
Now, rearrange the equation with similar terms on each side,
3x + 3x - 6x = 3 +2 - 15
0 = -10, then there is no solution.
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Veronica bought an ICEE for $6 at the movies. She also bought some hot dogs for $3 each. Veronica did not want to spend more than $27 on the ICEE and hot dogs. Which inequality can be used to find h, the number of hot dogs Veronica could have bought?
Answer:
6 + 3h ≤ 27
Step-by-step explanation:
hope this helpsss
Larry paid $4.16 for 4 tomatoes. At this same rate, how much would 7 tomatoes cost?
-$11.16
-$7.28
-$7.00
-$2.38
Answer:
7.28
Step-by-step explanation:
You have to know the same rate for $4.16 for 4 tomatoes. Think about it
A right triangle has a leg of length 12 and a hypotenuse of length 23 yards. Find the length of the other leg (nearest tenth).
2.5 ( y + ⅖ ) = -13
im really bad at math someone pls help
Answer:
-5.6
Step-by-step explanation:
first distribute the 2.5
also convert the 2/5 to decimal (0.4) because it's hard to work with both decimal and fraction
2.5y + 2.5*0.4 = -13
2.5y +1 = -13
y = -14/2.5 = -5.6
look at screenshot and answer question
Answer:
32x +20
Step-by-step explanation:
Answer:
32x+20
Step-by-step explanation:
If you use distributive property you would multiply each number by 4. 4 times 8x is 32x and 4 times 5 is 20, and when you put those together you get 32x+20!
I hope this helps, and have a great day!
To map △PQR onto △STU, there must be a factor k that reduces △PQR.
Find each length.
PQ = 5
QR = 7
ST = 5
TU = 5
Step 2 out of 5:
If kPQ = ST, then k =
Answer: k=1
Step-by-step explanation: PQ already equals ST
SOMEONE PLZZZ HELP MEE WHATS THE ANSWER AND EXPLAIN WHY IM GIVING 25 BRAINLIEST!!
Answer:
15
Step-by-step explanation:
75.00 - 20% is 60
60 + (tax 15) is 75.00
So I'm guessing that the tax rate is 15
Maria is reading a book that has 237 pages. She
already read some of it last week. She plans to read 30
pages tomorrow. By then, she will be of the way
through the book. How many pages did Maria read
last week?
Answer:
49 pages
237/3 = 79.
30+49 = 79
Team Green and Team Blue play in a competition. Team Green has twelve more points than Team Blue.
Team Green has four times as many points as Team Blue.
How many points does each team have?
Answer:
Team blue points = 4 points
Team green points = 16 points
Step-by-step explanation:
Let
Team blue points = x
Team green points = (x + 12) points (1)
Team green points = 4x (2)
Equate equation (1) and (2)
x + 12 = 4x
12 = 4x - x
12 = 3x
x = 12/3
x = 4 points
Team blue points = x
= 4 points
Team green points = (x + 12)
= 4 + 12
= 16 points
Team green points = 4x
= 4(4)
= 16 points
Which of the following is the product (5y − 3)2?
Answer:
= 10y − 6 is your answer
Step-by-step explanation:
option B is correct, 25y²-30y+9 is the product of (5y − 3)².
What is Expression?The combination of numbers, variables, and operators is known as Expression.
The given expression is (5y − 3)²
The process of determining the product of two or more numbers is Multiplication.
The expression is five times of y minus three to the power of two.
From algebraic identity we have (a-b)²=a²+b²-2ab
Now (5y − 3)²
(5y)²+3²-2(5y)(3)
25y²+9-30y
Twenty five y to the power of two plus nine minus thirty times of y.
25y²-30y+9 is the expression after product of (5y − 3)².
Hence, option B is correct, 25y²-30y+9 is the product of (5y − 3)².
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Which of the following is the product (5y − 3)2?
A. 10y − 6
B. 25y2 − 30y + 9
C. 25y2 − 9
D. 25y2 + 30y − 9
Find the area of the parallelogram.
Answer:
12
Step-by-step explanation:
12 is the area
Since,
6×2=12
Have to find x,y and z.
Answer:
z= 2√2
x=2
y=2√2
If g(x) = 10 - 2x then which of the following is the value of g(7)?
Answer:
g(7)= -4
Step-by-step explanation:
10-2(7)
10-14
=-4
The value of g(7) is -4.
What is a function?A function is a relationship between inputs where each input is related to exactly one output.
Example:
f(x) = 2x + 1
f(1) = 2 + 1 = 3
f(2) = 2 x 2 + 1 = 4 + 1 = 5
The outputs of the functions are 3 and 5
The inputs of the function are 1 and 2.
We have,
g(x) = 10 - 2x
For x = 7,
g(7) = 10 - 2 x 7
g(7) = 10 - 14
g(7) = -4
Thus,
g(7) = -4.
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Write an equation that represents the line