To solve this question, we need to solve an exponential equation, which we do applying the natural logarithm to both sides of the equation, getting that it will take 7.6 years for for 21 of the trees to become infected.
Model:
The exponential model for the number of infected trees after t years is given by:
[tex]f(t) = e^{0.4t}[/tex]
How many years will it take for 21 of the trees to become infected?
This is t for which:
[tex]f(t) = 21[/tex]
Thus
[tex]e^{0.4t} = 21[/tex]
Applying the natural logarithm to both sides:
[tex]\ln{e^{0.4t}} = \ln{21}[/tex]
[tex]0.4t = \ln{21}[/tex]
[tex]t = \frac{\ln{21}}{0.4}[/tex]
[tex]t = 7.6[/tex]
It will take 7.6 years for for 21 of the trees to become infected.
For another example of a problem in which an exponential equation is solved, you can check brainly.com/question/24290183.
A square garden has area 1764meter find it's length and perimeter
Answer:
[tex]area \: of \: a \: squre = {a}^{2} \\ {a}^{2} = 176 \\ a = 13.26m \\ perimeter = 4a = 4 \times 13.26 = 53.04m^2 \\ thank \: you[/tex]
Answer:
Length = 42 mPerimeter = 168 mConcept:
Here, we need to know how to find the area and perimeter of the square.
Area (square) = s²
s = side lengthPerimeter (square) = 4s
s = side lengthSolve:
PART I: Find the lengthGiven information
Area = 1764 m²
Given formula
A = s²
Substitute values into the formula
1764 = s²
Square root both sides
√s² = √1764
[tex]\boxed{s=42m}[/tex]
--------------------------------------------------------------------------------------------------------
PART II: Find the perimeterGiven information
s = 42 m
Given formula
P = 4s
Substitute values into the formula
P = 4 (42)
Simplify by multiplication
[tex]\boxed{P=168m}[/tex]
Hope this helps!! :)
Please let me know if you have any questions
9.
A rocket is launched from the top of a 76-foot cliff with an initial velocity of 135 ft/s. a. Substitute the values into the vertical motion formula h = –16t2 + vt + c. Let h = 0. b. Use the quadratic formula to find out how long the rocket will take to hit the ground after it is launched. Round to the nearest tenth of a second.
A. 0 = –16t2 + 135t + 76; 0.5 s
B. 0 = –16t2 + 76t + 135; 9 s
C. 0 = –16t2 + 76t + 135; 0.5 s
D. 0 = –16t2 + 135t + 76; 9 s
Answer:
The answer is 2.)
Step-by-step explanation:
Given initial velocity=135 ft/s
& cliff=76 foot
Given quadratic equation
⇒ (let h=0 it is given)
⇒
⇒
⇒ t=8.96≈9 s (the other root is negative)
Hence, rocket will take 9 s to hit the ground after launched.
Answer: Choice D
0 = 16t^2 + 135t + 76; 9 s
==============================================
Explanation:
The equation we start with is
[tex]h = -16t^2 + vt + c\\\\[/tex]
where v is the starting or initial velocity, and c is the starting height.
We're told that v = 135 and c = 76
We let h = 0 to indicate when the object hits the ground, aka the height is 0 ft.
That means the equation updates to [tex]0 = -16t^2 + 135t + 76\\\\[/tex]
Based on that alone, the answer is between A or D
-------------------
We'll use the quadratic formula to solve for t
We have
a = -16b = 135c = 76So,
[tex]t = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\\\\t = \frac{-135 \pm \sqrt{135^2 - 4(-16)(76)}}{2(-16)}\\\\t = \frac{-135 \pm \sqrt{23,089}}{-32}\\\\t \approx \frac{-135 \pm 151.9506}{-32}\\\\t \approx \frac{-135 + 151.9506}{-32} \ \text{ or } \ t \approx \frac{-135 - 151.9506}{-32}\\\\t \approx \frac{16.9506}{-32} \ \text{ or } \ t \approx \frac{-286.9506}{-32}\\\\t \approx -0.52971 \ \text{ or } \ t \approx 8.96721\\\\[/tex]
We ignore the negative t value because a negative time duration makes no sense.
The only practical solution here is roughly 8.96721 which rounds to 9.0 or simply 9 when we round to the nearest tenth (one decimal place).
In short, the object will hit the ground at the 9 second mark roughly. Or put another way: the object is in the air for about 9 seconds.
From this, we can see that the final answer is choice D.
Keep in mind that we aren't accounting for any wind resistance. Considering this variable greatly complicates the problem and requires much higher level mathematics. So we just assume that there is no wind at this moment.
Sayad bought a watch and sold to Dakshes at 10% profit. Sayad again sold it to Sahayata for rs 6,050 at 10% profit. i)Find the cost price of Dakshes. ii) Find the cost price of Sayad.
Answer:
The cost price of Dakshes was $ 5,500, while the cost price of Sayad was $ 5,000.
Step-by-step explanation:
Given that Sayad bought a watch and sold to Dakshes at 10% profit, and Dakshes again sold it to Sahayata for $ 6,050 at 10% profit, to find the cost price of Dakshes and the cost price of Sayad the following calculations must be performed:
6,050 / 1.1 = X
5,500 = X
5,500 / 1.1 = X
5,000 = X
Therefore, the cost price of Dakshes was $ 5,500, while the cost price of Sayad was $ 5,000.
find the value of a and b if [tex]5+√3/7+2√3=a-b√3[/tex]
Answer:
The values of [tex]a[/tex] and [tex]b[/tex] are [tex]5[/tex] and [tex]-\frac{15}{7}[/tex], respectively.
Step-by-step explanation:
There are mistakes in the statement, correct form is presented below:
[tex]5+\frac{\sqrt{3}}{7} + 2\sqrt{3} = a - b\cdot \sqrt{3}[/tex].
By direct comparison we have the following system of equations:
[tex]a = 5[/tex] (1)
[tex]\frac{\sqrt{3}}{7}+2\sqrt{3} = -b\cdot \sqrt{3}[/tex] (2)
In (2) we solve for [tex]b[/tex]:
[tex]\left(\frac{1}{7}+2 \right)\cdot \sqrt{3} = -b\cdot \sqrt{3}[/tex]
[tex]b = -\frac{15}{7}[/tex]
The values of [tex]a[/tex] and [tex]b[/tex] are [tex]5[/tex] and [tex]-\frac{15}{7}[/tex], respectively.
Which quadratic formula do I need to use to solve 2x(x+1.5)=-1
Answer:
x = - 1, x = - 0.5
Step-by-step explanation:
Given
2x(x + 1.5) = - 1 ← distribute parenthesis on left side
2x² + 3x = - 1 ( add 1 to both sides )
2x² + 3x + 1 = 0 ← in standard form
(2x + 1)(x + 1) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 1 = 0 ⇒ x = - 1
2x + 1 = 0 ⇒ 2x = - 1 ⇒ x = - 0.5
often contains information about the author's experiences with the subject matter of
9. The author's introduction to a book, also called a/an
the book.
A. glossary
B. Index
C. table of contents
D. preface
Im quite sure it’s d wanna make sure
Which rules define the function graphed below? (15 points cuz I'm stumped)
y=2x+3; y=-1/3x+3
y=2x; y=-1/3x
y=3x+2; y=3x-1
y=-3x+3; y=x+3
Answer: Choice A
y=2x+3; y=-1/3x+3
==================================================
Explanation:
The left portion of the blue curve is y = 2x+3 but it is only graphed when x < 0 (we could argue that [tex]x \le 0[/tex] but I'll set that aside for the other portion).
The right portion is the line y = -1/3x + 3 and it's only graphed when [tex]x \ge 0[/tex]
So we could have this piecewise function
[tex]f(x) = \begin{cases}2x+3 \ \text{ if } x < 0\\-\frac{1}{3}x+3 \ \text{ if } x \ge 0\\\end{cases}[/tex]
Or we could easily swap the "or equal to" portion to move to the first part instead like this
[tex]f(x) = \begin{cases}2x+3 \ \text{ if } x \le 0\\-\frac{1}{3}x+3 \ \text{ if } x > 0\\\end{cases}[/tex]
Either way, we're involving the equations mentioned in choice A
I really really need help with this
Answer:
c) 21
Step-by-step explanation:
[tex] \sqrt{169} + \sqrt{64} [/tex]
13+8
answer is 21
Solve BCD. Round the answers to the nearest hundredth, if necessary.
Answer:
B
Step-by-step explanation:
here we use trigonometric ratio involving soh,cah,toa
Jia baked two kinds of muffins. She baked 27 blueberry muffins. The number of cranberry muffins she baked is represented by the equation shown.
27 ÷ 3 = 9
Which statement accurately compares the number of blueberry muffins and the number of cranberry muffins?
Jia baked 3 times as many blueberry muffins as cranberry muffins.
Jia baked 9 times as many blueberry muffins as cranberry muffins.
Jia baked 3 times as many cranberry muffins as blueberry muffins.
Jia baked 9 times as many cranberry muffins as blueberry muffins.
Answer:
she baked 3 times as many cranberry than blueberry muffins
Step-by-step explanation:
i think that because 9×3=27
the amount of the cranberry muffins are 9
Analyze the diagram below and complete the instructions that follow.
10
6
B.
'C С
8
Find sin ZA
A 3
5
B. 4
C 1
Answer:
B. 4/5
Step-by-step explanation:
Sin = Opposite/Hypotenuse
Sin∠A = 8/10 = 4/5
i  genuinely dont know help
Answer:
-13 1/2 < -6/8
Step-by-step explanation:
*Any negative in either the numerator or denominator will make the entire fraction negative.
1/2 = .5
-13 1/2 = -13.5
-6/8 = -3/4
-3/4 = -0.75
-6/8 = -0.75
-13 1/2 = -13.5
Which means:
-13 1/2 < -6/8
Hope this helped.
Answer:
[tex] < [/tex]
Step-by-step explanation:
[tex] \frac{6}{8} [/tex]
Is close to 0 (to positive) you can use a time line to determine which is a correct answer
Which graph represents a linear function
Answer:
c on edge
Step-by-step explanation:
What are the coordinates of the vertices of the image?
A) A'(9,8), B'(-3,-4), C'(1, 2), and D'(1,-2)
B) A'(3,4), B'(3,-4), C'(-5, 2), and D'(1, 2)
C) A'(3,8), B'(-3, 4), C'(1,-2), and D'(-1,2)
D) A'(-3, 4), B'(3,4), C'(5,-2), and D'(-1,-2)
Answer:
D
Step-by-step explanation:
I took the quiz
Identify a transformation of the function f(x)
x2 by observing the equation of the function g(x) = (x - 6)^2
Answer:
2nd option
Step-by-step explanation:
Given f(x) then f(x + a) is a horizontal translation of f(x)
• If a > 0 then a shift left of a units
• If a < 0 then a shift right of a units
Here g(x) = (x - 6)²
The base graph has been shifted right 6 units
what is the commutative property for 4xy
PLEASE ANSWER QUICKLY
Answer:
[tex]we \: know \: that \: commutative \: prop \\ = x + y = y + x \\ then \\ 4xy + 0 = 0 + 4xy \\ thank \: you[/tex]
round 1.89 to one decimal place
Answer:
1.9
Step-by-step explanation:
You round when the numbers behind the decimal are 5 or greater. This being said, you need to round from the number furthest away from the decimal. In this case it would be 9. 9 is greater than 5 so we round 8 up to 9 and get rid of the number behind it. We are left with 1.9
Urgent ! Help me please
Answer:
B
Step-by-step explanation:
x -> x and y -> y+5
-1 -> - 1 and - 3 -> 2, so b is the correct answer.
I need help right now ASAP!!!please man some on help me
Answer:
hope it helps
Step-by-step explanation:
Answer:
Step-by-step explanation:
S is the midpoint of QR.
⇒ RS = QS
QR ⊥ PS
⇒ ∠RSP = ∠QSP = 90°
In ΔPSR & ΔPSQ,
Statement Reason
RS ≅ QS S is midpoint of QR
∠RSP ≅ ∠QSP QR ⊥ PS
PS ≅ PS Reflexive property
ΔPSR ≅ ΔPSQ Side Angle Side - S A S Congruent
PR≅ PQ CPCTC
If f(x)=7 find x=-3
A.4
B.-3
C.7
D.-4
Answer: the answer to your question is 7
Step-by-step explanation:
paul leaves for school at 7:25 am he returned home at 3:15 pm how long was paul away from home?
Answer:
8 hours 10 minutes
I hope this answers your question
Answer: paul has been away from home for 7 hours and 50 minutes.
Step-by-step explanation:
f(x) = x+3
g(x) = 2x^2-4
find (f times g) (x)
Step-by-step explanation:
(f*g) (x)=f(x) * g(x)
=(x+3)(2x^2-4)
=2x^3-4x+6x^2-12
What are the different ways you can solve a system of linear equations in two variables? What is the process for solving a system using each method?
39.) Fiona bought a brand new Harley Davidson motorcycle. Since the weather was nice, she decided to go out for a ride with some of her friends. Before leaving town, she stopped to fill up her motorcycle with gas so that she had a full tank. If Fiona's motorcycle has a 4 gallon gas tank, and she only had to add 2 4/7 gallons, how much gas was in the tank before she filled up?
Answer:
1 3/7 gallonsStep-by-step explanation:
Let the amount of gas in the tank before filling was x.
We have:
x + 2 4/7 = 4x = 4 - 2 4/7x = 2 - 4/7x = 1 3/7 gallonslet the amount of gas be x
[tex]\\ \sf\longmapsto x+2\dfrac{4}{7}=4[/tex]
[tex]\\ \sf\longmapsto x+\dfrac{18}{7}=4[/tex]
[tex]\\ \sf\longmapsto x=4-\dfrac{18}{7}[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{28-18}{7}[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{10}{7}[/tex]
[tex]\\ \sf\longmapsto x=1\dfrac{3}{7}[/tex]
what's the formula of
(a+b)³ = ?
Answer:
(a+b)³=a³+3a²b+3ab²+b³
Answer:
Step-by-step explanation:
Hello!
(a+b)(a+b)(a+b)
(a+b)(a+b) = a²+2ab + b²
(a²+2ab + b²) (a+b)=
a³ + a²b + 2a²b + 2ab² + ab² + b³ =
a³ + b³ + 2a²b + 2ab² + ab² + a²b
in the first quarter austin played for 4 minutes and 30 seconds. wyatt played for 310 seconds who had more playing time
Answer:
wyatt
Step-by-step explanation:
4:30 mins is 270 seconds
sentence
After several days of drilling, a water well is 80
meters deep. The well is being drilled at a rate of
20 meters per day.
How many more days will it take to reach a total
depth of 180 meters?
Answer:
it will take 5days to reach a total of 180meters
Step-by-step explanation:
80m+20+20+20+20+20
=180meters
=5days
The membership fee for joining a gardening association is
$24 per year. A local botanical garden charges members of the gardening association
$3 for admission to the garden. Nonmembers of the association are charred $6.
After how many visits to the garden is the total cost for members, including the
the total cost for nonmembers?
Hi.
Let's call X number of visits.
so members pay for a year : membership 24 and reduce entrance at 3 dollars.
so you member pay : 3X+24
a non member pay entrance fee of 6 for each visit.
so 6X
Question : for how many visit would a membership will be more intresting than standar entrance ?
3X+24 = 6X
3X-6X = -24
-3X=-24
X= -24/-3
X =24/3
X= 8
Under 8 visit a year, it's cheaper non being a member.
at 8 entrance cost is the same for members and non member. After it better to choose membership as
9 entrances for member is : 3x9 +24 = 27+24= 51
non member : 9x6 = 54
And so on for each supplementary visits.
10700 by 100 + 5192by 1000 - 412
Answer:
the answer is -299.808 well that's what I think it's
Answer:
-299.808
Step-by-step explanation:
= 10700/100 + 5192/100 - 412
= 107 + 5.192 - 412
= -299.808
If the areas of two similar triangles are equal, prove that they are congruent
Refer the attached image for the answer
HOPE SO IT HELPS YOU