Given:
Present number of trees = 2.5 billions
Rate of decrease = 0.5% per month
To find:
The expression that represents how many trees will be left in 10 years?
Solution:
Exponential decay model:
[tex]P(t)=a(1-r)^t[/tex] ...(i)
where, a is initial value, r is decreasing rate and t is time period.
We have,
a = 2.5 billions
r = 0.5% = 0.005 per month
t = 10 years = 120 months [1 year = 12 months]
Putting a=2.5, r=0.005 and t=120 in (i), we get
[tex]P(120)=2.5(1-0.005)^{120}[/tex]
[tex]P(120)=2.5(0.995)^{120}[/tex]
[tex]P(120)=1.3699657[/tex]
[tex]P(120)\approx 1.37[/tex]
Therefore, the required expression is [tex]2.5(1-0.005)^{120}[/tex] and the remaining trees after 10 years is about 1.37 billions.
What is 7 1/2% of 60?
Answer:
the answer is 4.5. hope this helps
If you can, please leave an explanation so I can learn how to do it rathe than just copying
Answer:
Point-Slope: y+1=-5/7(x-5)
Slope Intercept: y=-5/7x+ 2 4/7
Standard: -5x+7y=18
Step-by-step explanation:
Slope: -5/7
Point slope is when the equation is in y-y1=m(x-x1) form.
I used the point (5,-1) but it really doesn't matter which one
Substitute it into (x1,y1)
y--1=-5/7(x-5)
y+1=-5/7(x-5) **2 minus signs is equal to 1 plus sign**
Slope-intercept is when the equation is in y=mx+b form.
y=-5/7x+b
To solve for b, plug in one of the points (again, I choose to use (5,-1)
(-1)=-5/7(5)+b
-1=-25/7+b is equal to asking -1=-3 4/7+b
b=2 4/7
Standard form is when it is in Ax+By=C
We'll covert from slope intercept to standard: y=-5/7+ 2 4/7
y=-5/7x+ 2 4/7 is the same as y=(-5/7x+ 18/7)
7y=5x+18 **Multiply both sides by 7, the common denominators**
-5x+7y=18 **Subtract 5x from both sides**
Sorry it took it while to get everything down but I hope this helps~
divide the sum of 3.19 and 2.39 by 3.6
Answer:
1.55
Step-by-step explanation:
3.19 + 2.39 = 5.58
5.58 / 3.6 = 1.55
Martin has a total of 19 nickels (50.05) and dimes ($0.10) worth $1.65. How many of each type of coin does he have?
can put your work too
Answer: 19nickels and 7dimes.
Ps i really don’t know where the 50.05 came from if it is suppose to be there then I really don’t know how to solve this.
Step-by-step explanation:
Ok so if you know that there are 19nickels, let n=number of nickels.
The number of total coins subtracted by number of nickels will give you number of dimes.
165-number of nickels=number of dimes
Value of dimes=10(number of dimes) or total value of dimes/individual value (10cent)
Then you can substitute total as $1.65 and get the value of nickels by multiplying by 5cent ( my teacher taught me using whole numbers to make it easier so I turned $1.65 to 165 cent). Since the value of the dimes is the value of nickels subtracted from the total, I can subtract 95 from 165 and divide the difference by 10, to get the number of dimes.
5(n)=5(19)=95
(165-95)/10=number of dimes
70/10=7dimes
You can check by multiplying 7x10 and 5x15 again and adding them together to see if they equal 165 cent.
4-3y+(-7y)+6.9=
Fast PLZ!
Please help me!
Will mark brailest if you are right!!!
Answer:
f(x) = 3x
Step-by-step explanation:
The equation of a line passing through the origin is
y = mx ( m is the slope )
Calculate m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (0, 0) and (x₂, y₂ ) = (1, 3)
m = [tex]\frac{3-0}{1-0}[/tex] = 3 , then
y = 3x ← is the equation of the graphed line
find measure of angle 1
Identify the correct Triangle Congruence Theorem statement that describes the figure below.
Ο BAC & FED
O ABC & DEF
O ABC & DFE
О АСВ & DEF
Determine the width of the pond. (Write your answer without the unit)
Can someone help plzzzzz
Answer:
17
Step-by-step explanation:
A bag contains orange, white, and purple marbles. If you randomly
choose a marble from the bag, there is a 23% chance of drawing an
orange marble and a 48% chance of drawing a white marble. What is the
probability of choosing a purple marble? Express your answer as a
percent
Answer:
29%
Step-by-step explanation:
48%+23%= 71%
100%-71%=29%
The temperature dropped 6°C every hour for 6 hours. What was the total number of degrees the
temperature changed in the 6 hours?
The total change in the temperature was
loc.
(3 + 81)(3 - 81) =
DONE
h
Answer:
-6552
Step-by-step explanation:
First do 3+81 = 84 then 3-81 = -78. Then multiply them together to get -6552
Answer:
（3 + 81）（3-81）=9-6561
Stepby-step explanation:
Aaron can mow 2400 square feet in 3/4 of an hour. How fast can he
mow in square feet per hour
Answer:
he mow in square feet per hour : 2400 x (4/3) =3200 square feet/ per hour
Step-by-step explanation:
The school has 330 students in 11 classrooms. What is the unit rate of
students per classroom? Explain how you got your answer.
What is the value of x?
Answer:
x = 6
Step-by-step explanation:
The Pythagorean Theorem states that a² + b² = c². In this case, c would be the hypothenuse or the longest side, which is 10. 8 can be either a or b.
a² + b² = c²
a² + 8² = 10²
a² + 64 = 100
a² = 36
a = √36
a = 6
So, x = 6.
Hope that helps.
Which of the options below show a pair of supplementary angles? Select all that apply.
A) 160°, 20°
B) 120°, 40°
C) 45°, 135°
D) 30°, 120°
Answer:
A and C
Step-by-step explanation:
A) 160 + 20 = 180
B) 120 + 40 = 160
C) 45 + 135 = 180
D) 30 + 120 = 150
All supplementary angles must add up to 180 degrees.
CAN SOMEONE PLEASE HELP ME???
Answer:
m=2
Step-by-step explanation:
slope is the average rate of change in a specific interval
we can calculate slope in this case with Δy/Δx or (y2-y1)/(x2-x1)
m=(y2-y1)/(x2-x1)
=(-1-7)/(-3-1)
=-8/-4
=2
PLEASE ANSWER QUICKLY! I WILL GIVE BRAINLIEST.
What is 5/6 of 1/2?
A. 5/12
B. 6/12
C. 5/8
D. 6/8
Answer:
5/12
Step-by-step explanation:
of means multiplication. so multiply 5x2 / 6x2 which is 5/12
Answer:
A. 5/12
Step-by-step explanation:
the "of" in the answer is asking you to multiply.
what you want to do is multiply the numerators and denominators.
5 x 1 = 5
6 x 2= 12
giving you 5/12!
hope this helps <3
How could you calculate 23 x 21 if the 2 button on your calculator is broken?
Answer:
Well you could get use g o o g l e s calculator or write it out.
Step-by-step explanation:
Step-by-step explanation:
(30-7)*(30-9) I think this may be an answer
how is 1/5 changed to a decimal
Answer:
just divide 1/5 by 100 and you should get it
Step-by-step explanation:
Help me find the values of k and p please
Answer:
B
Step-by-step explanation:
The lines marked with ||| are equal. That means that 2P + 7 equals 17
2P + 7 = 17 Subtract 7 from both sides.
2P + 7 - 7 = 17 - 7 Combine
2P = 10 Divide by 2
P = 5
3k - 5 and 28 are marked with one | That means that they are equal
3k - 5 = 28
3k = 28 + 5
3k = 33
k = 33/3
k = 11
The answer is B
need help step by step -5 + g = -2
Answer:
g=3
Step-by-step explanation:
I'm going to explain this thoroughly because it seems like you don't have a full understanding of how to do this...practice makes perfect though!
-5+g=-2
The entire point of completing an algebra problem is to find what the variable equals, which means that we need to get the variable by itself. In this case, the variable is g.
The only other thing that is next to g is -5, so we need to add 5 because it is the opposite of subtracting (the sign also always changes when something crosses to the other side of the equation).
-5+g=-2
+5 +5
g=3
This is the solution! I would suggest that you practice these type of small algebra problems if you really don't understand c:
I hope this helped!! Have a nice day .3.
What are the solutions to the equation x2 - 2x - 15 =0?
Answer:
x=−3 or x=5
so yeah
Answer:
solve for x
Step-by-step explanation:
i hope this helps
what is the degree of the expression below? x^2-3x+7
Answer:
2
Step-by-step explanation:
Which Unit lengths represent the sides of a right triangle
A. 3,4 and 5
B. 6, 8 and 15
C. 20, 21 and 29
D. 9, 12 and 15
Answer:
A 3, 4 and 5
Step-by-step explanation:
so far two-thirds of the seniors bought prom tickets. if they need minimum of 250 people to attend in order to keep the venue, how many students must be in the senior class to ensure they sold enough tickets
Answer: 375
Step-by-step explanation:
2/3 of x= 250
250 x 3=750
750//=375
They need a minimum of 375 students in order to keep the venue,
What is the percentage?A percentage is a value per hundredth. Percentages can be converted into decimals and fractions by dividing the percentage value by a hundred.
Given, So far two-thirds of the seniors bought prom tickets. if they need a minimum of 250 people to attend in order to keep the venue.
Assuming they need a minimum of x people.
∴ (2/3)x = 250.
2x = 750.
x = 375.
learn more about percentages here :
https://brainly.com/question/24159063
#SPJ2
Simplify the expression:
8(1 + 8z) =
Submit
Answer: My answer is in the bottom :)
Step-by-step explanation:8(1 + 8z) do the distributive property
8+64z=72z or 8=64z
64 64
1/8=z
BOT
Kimberly baked 2 dozen cupcakes for her
classmates. Two-thirds of the cupcakes
were vanila and the rest were chocolate.
How many cupcakes were chocolate?
A 12
B 16
C 4
D 8
.....
Teaching with Tifany
5.31
Answer:
the correct answer is D) 8
Step-by-step explanation:
2 dozen= 24
2/3 of 24 is 16
24-+6=8
therefore, 8 of the cupcakes were chocolate
What is the value of x?
......................
Hey again!
The answer to your question is 14.54 inches
We can find this by doing 1454/100, and that is 14.54.
Hope it helps, have a great day! Let me know if there's more to help with.