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 the circumference of a circle with radius 2.1 cm? Use > (inserts wavey = sign) 3.14.
Step-by-step explanation:
The formula for the circumference of a circle is 2*pi*radius
Circumference = 2(3.14)(2.1)
= 13.188cm
A ball dropped from the roof of a 120 foot high building took 4 seconds to reach the ground. What was the average speed of the ball during its fall?
A
480 feet per second
B
124 feet per second
C
30 feet per second
D
130 feet per second
Answer:
answer is C
average speed=distance÷time=120÷4=30
Write a real-world problem that is represented by the inequality below. x >5
Pls help and show working/explain
Answer:
C. Corresponding angles
Step-by-step explanation:
Hope this helps!
Please mark me brainliest if you can. :)
Please help it’s urgent !!
Answer:
2 is the correct answer you know it also
Hey I need to survey 10 people who play video games so please answer or comment your answers down below :)
Survey ten people who play video games. Ask them these questions:
Why do you play video games?
What types of games do you play?
How long have you been playing video games?
How do you think video games will be played in the future?
Do you think video games will converge to a single platform in the future?
Thanks <3
Playing video games helps me if I have a rough time, I started around 2019. I play adventour type video games, not sure if raft counts, but that is a game I play too often with my friends. I think that video games probably could be played in cars as well but I dont know what else it can be or will be played on. Definitely will not be a single platform, people are too greedy everyone wants a better state then others. (not sure if that makes sense)
hope this helps :))
Solve the following system of equations:
y=2x + 1
y = -x+4
x= ?
y=?
Answer:
x= 1, y=3
Step-by-step explanation:
y= 2x +1
y= -x +4
Those two equation are in a system that means they need to be true in the same time. Just like I would say look for a car that is red and is a truck in this case we look for x and y is true that y = 2x+1 and is true that y= =x+4.
so y= 2x+1 but y is -x+4 so substitute
-x+4 = 2x +1, add x on both sides
4= 2x+x +1, subtract 1 from both sides
4-1 = 2x +x, combine like terms
3 = 3x , divide both sides by 3
x=1
if x=1 we substitute in y= -1 +4 = 3
What is the values of 6.6.6.6
Step-by-step explanation:
I just need points sorry
Answer:
1296
Step-by-step explanation:
6 times 6 = 36 and 36 times 6=216 and 216 times 6 = 1296
please help me !!!!
Flying against the wind , an airplane travels 3660 kilometers in 6 hours. flying with the wind , the same plane travels 3800 kilometers in 4 hours. what is the rate of the plane in still air and what is the rate of the wind?
Answer:
...
against the wind, an airplane travels 3640 km in 7 hours.
with the wind, the same plane travels 6000 km in 6hrs.
...
let speed of plane in still air be x mph
speed of wind be y mph.
..
t=d/r
..
against wind speed = x-y mph
with wond speed = x=y mph
...
3640/(x-y)=7
3640 = 7x-7y
/7
520=x-y.....................1
...
6000/x+y = 6
6000 = 6x+6y
/6
1000=x+y.....................2
...
Add (1) & (2)
2x=1520
/2
x=760 mph speed of plane in still air
...
plug value of x in 2
1000=760+y
100-760=y
240 = y
240 mph speed of wind
What is the area of the semi circle if the diameter is 10 cm
Answer:
39.25 cm
Step-by-step explanation:
The formula for a circle is pi x radius x radius.
So to get the radius, you multiply 10 and 1/2. You should get 5. Then you multiply 5 by 5. You should get 25.
Then you multiply 3.14 and 25. You should get 78.5.
The last step is to divide 2 by 78.5. You should get 39.25
Answer:
39.25 cm
Step-by-step explanation:
A = 3.14 x r^2 / 2
if the diameter is 10 then the radius is 5
A = 3.14 x 5^2 / 2
A = 3.14 x 25 / 2
A = 78.5 / 2
A = 39.25
Find the perimeter of the triangle
Answer:
8 feet
Step-by-step explanation:
hope it helps! :)
Answer:
8 feet
Step-by-step explanation:
When calculating mixed numbers, I like to make all the numbers to improper fractions with the same denominators first before evaluating.
Perimeter of triangle = 2[tex]\frac{3}{8}[/tex] + 2[tex]\frac{3}{8}[/tex] + 3[tex]\frac{1}{4}[/tex]
= [tex]\frac{19}{8}[/tex] + [tex]\frac{19}{8}[/tex] + [tex]\frac{13}{4}[/tex]
= [tex]\frac{19}{8}[/tex] + [tex]\frac{19}{8}[/tex] + [tex]\frac{26}{8}[/tex]
= [tex]\frac{64}{8}[/tex]
= 8 feet
PLEASE HELP FAST !!!
What is the equation of the line in slope-intercept form?
Answer:
y = 4/3x + 4
Step-by-step explanation:
guys please help this is a math question
Answer:
81.5
Step-by-step explanation:
<G and <H are congruent
<F and <I are congruent
so the last two angles in both triangles must also be congruent
this means that <K and <J are congruent
so we can create this equation: <K = <J
substitute the angles with what we know: 4[tex]y^{2}[/tex] = 6[tex]y^{2}[/tex] - 40
add 40 to both sides and subtract 4[tex]y^{2}[/tex] from both sides: 40 = 2[tex]y^{2}[/tex]
you get: 20 = [tex]y^{2}[/tex]
root square on both sides: [tex]\sqrt{20}[/tex] = [tex]\sqrt{y^{2} }[/tex]
you get: y ≈ 4.5
substitute this into one of the equations for a missing variable:
6[tex]y^{2}[/tex] -----> 6 (4.5 x 4.5) - 40
6 ( 20.25) - 40
121.5 - 40
81.5
Which equation is true?
O 1150) = - 150
01 - 150 = 150
- 150 = 150
O-1 - 150= 150
THe 3rd equation is true
i bet nobody will anser this =P. Solve 52.425 divided by 0.5
Answer:
104.85
Step-by-step explanation:
c:
Answer:
104.85
Step-by-step explanation:
52.425/0.5=104.85
The area of a rectangular pool table is: x2 + 14x +40. What are the dimensions of the table?
Formula: Area = (L) (W)
A(x + 8)(x + 5)
B(x + 20)(x - 2)
C(x + 4)(x + 10)
D(x +14)(x + 40)
Answer:
the width is (x + 4) and the length is (x + 10)
Step-by-step explanation:
The area of a rectangle is given by A = L * W, where L is the length and W the width.
If we factor the given x^2 + 14x + 40, we get (x + 10)(x + 4). Thus, the width is (x + 4) and the length is (x + 10).
need answer fast!
Find the product of ( 2x^2 − 4x + 3 ) ( 3x + 6 ) using the box method shown below. What will the monomial be in the box marked with a B?
Select one:
a. - 12x 2
b. - x 2
c. - x
d. - 12x
Answer:
[tex]-12x^2[/tex]
Step-by-step explanation:
Think of the box method as completing a chart or a multiplication table.
We can see that box B is in the second column of the first row. The second column is labeled by -4x. The first row is labeled by 3x. So, in order to fill out box B, you have to multiply -4x and 3x together.
To do so, multiply the terms' coefficients (the numbers in front of the variable). -4 times 3 makes -12. Then, multiply the variables - just keep the variable and add their exponents. x and x both have exponents of one, which makes [tex]x^1^+^1[/tex], resulting in [tex]x^2[/tex]. Put them together and the answer would be [tex]-12x^2[/tex].
18. A figure is said to be regular if its sides are equal in length and angles are equal in
measure. What do you mean by a regular quadrilateral?
Answer:
If its 4 sides need to be equal and 4 angles need to be equal then it is a square.
Step-by-step explanation:
[tex]\huge\sf\fcolorbox{green}{pink}{Answer}[/tex]
Properties of regular quadrilateral :- All sides are equalAll angles are 90° ( equal)Square is only the regular quadrilateral
A museum recorded that it had 988 visitors in 4 hours. What is the unit rate in visitors per hour?
A.). 222
B.) 247
C.). 249
D.). 262
6h+(-7.9d)-13+6d-2.8h
Answer:
=−1.9d+3.2h−13
Step-by-step explanation:
hope it helps and have a good day
Find the solution set to 3(2x - 4) > 2(x + 4)
Answer:
X>5
Step-by-step explanation:
So first distribut the numbers
6x-12>2x+8
now subtrct 2x on both sides
4x-12>8
Now add 12 on both sides
4x>20
x>5
Answer: > 5
Step-by-step explanation: I just know
Which of the equations can be used to solve for the value of X?
A. 2x = 52
B. 2x + 54 = 90
C. 2x + 52 = 180
D. 2x + 52 + 90 = 180
Answer:
The answer is A.
the angles are opposite angles, therefore they have the same value. they're equal to each other. you set them equal to each other to find the value of x.
Step-by-step explanation:
i hope this helps :)
solve the inequality
1/3x+8≤11
Answer:
x ≤ 9
Step-by-step explanation:
First, Isolate the variable by subtracting 8.
1/3x<= 3
Multiply both sides by 3
x<= 9
Answer:
x≤9
Step-by-step explanation:
Step 1: Subract 8 from both sides.
1/3x+8-8≤11-8
1/3x ≤3
Step 2: Multiply both sides by 3.
3*(1/3x)≤(3)*(3)
x≤9
A pair of jeans were originally $15.00. Monica received a 20%
discount. She paid 5% sales tax. What is the final cost Monica
paid for the jeans?
A.$12.60
B. $18.90
c. $40.00
D. $75.50
someone please help
Donald bought a box of golf balls for $9.31. There were 18 golf balls in the box.
About how much did each golf ball cost? Rename the decimal dividend as a whole number that is compatible with the divisor to estimate the quotient.
Step-by-step explanation:
Cost of each golf ball = $9.31 / 18
≈ $9 / 18 = $0.5.
Answer: 0.5172222222222222
Step-by-step explanation: divide 18 by 9.31
What is (a^2-b^2) factored out?
Answer:
(a+b)(a-b)
Step-by-step explanation:
because (a+b)(a-b):
If you use FOIL it will work backwards
Help Fast. The question is in an image because there is a graph to see.
Answer:
the answer is (3, 2)
Step-by-step explanation:
the formula to find the centroid of a triangle is
{( x1+x2+x3)/3 , ( y1+y2+y3)/3}
marking people brainlist 7s-s=
Answer:
6s
Step-by-step explanation:
what is the area of xyz
hiii please help! i’ll give brainliest if you give a correct answer tysm!
Answer: 3/16
Step-by-step explanation:
Reduce the expression, if possible, by cancelling the common factors.
