Answer:
19.3 years
Step-by-step explanation:
Given that the initial mass of a sample of Element X is 100 grams,
The formula is given as:
N(t) = No × (1/2) ^t/t½
Element X is a radioactive isotope such that every 30 years, its mass decreases by half.
N(t) = Mass after time (t)
No = Initial mass = 100 grams
t½ = Half life = 30 grams
N(t) = 100 × (1/2) ^t/30
How long would it be until the mass of the sample reached 64 grams, to the nearest tenth of a year?
This means we are to find the time
N(t) = 100 × (1/2) ^t/30
N(t) = 64 grams
64 = 100(1/2)^t/30
Divide both sides by 100
64/100 = 100(1/2)^t/30/100
0.64 = (1/2)^t/30
Take the Log of both sides
log 0.64 = log (1/2)^t/30
log 0.64 = t/30(1/2)
t = 19.315685693242 years
Approximately = 19.3 years
100 POINTS PLEASE ANSWER QUICK
Answer:
c the answer is c
Step-by-step explanation:
Answer:
The answer is B
Step-by-step explanation:
Mark as Brainllest
Pls explain how to do this
Answer:
3 1/12 miles
Step-by-step explanation:
[tex]6\frac{3}{4} -3\frac{2}{3} \\\\=\frac{27}{4} -\frac{11}{3}\\\\ =\frac{81}{12} -\frac{44}{12} \\\\=\frac{37}{12}\\\\=3\frac{1}{12}[/tex]
Make them into mixed fractions and then find the least common denominator (12). solve.
answer for brainilest and 11 points
Answer:
-16/3
Step-by-step explanation:
I am not sure if you are aware of this but I am not sure if you are aware of the fact
given 2x - 9y - 12 = 0, express 5x - 4y + 7 = 0 in terms of x only
Answer:
[tex]4 \frac{1}{9}x[/tex] + [tex]12\frac{1}{3}[/tex] = 0
Step-by-step explanation:
Based on 2x - 9y - 12 = 0
-9y = 12 - 2x
9y = -12 + 2x
y = [tex]-1\frac{1}{3} + \frac{2}{9} x[/tex]
Therefore...
5x - 4y + 7 = 0
5x - 4([tex]-1\frac{1}{3} + \frac{2}{9} x[/tex]) + 7 = 0
5x + [tex]5\frac{1}{3}[/tex] - [tex]\frac{8}{9} x[/tex] + 7 = 0
[tex]4 \frac{1}{9}x[/tex] + [tex]12\frac{1}{3}[/tex] = 0
The diameter of a circle is 20 meters. What is the circumference?
Step-by-step explanation:
C≈62.83m
Using the formulas
C=2πr
d=2r
Solving forC
C=πd=π·20≈62.83185m
F(x)=x^2. What is g(x)?
A. G(x)= x^2–4
B. g(x)= x^2+4
C. g(x)= -x^2-4
D. g(x)= -4x^2
Answer:
C
Step-by-step explanation:
I'm super sorry if I get this wrong you don't have to choose C I feel like I'm wrong but have a nice day
Find two numbers that multiply to -36 and add to -5.
Type below no links
Answer:
-6 times 6= -36
-36 + 31 = 5
Step-by-step explanation:
What two number does the cube root of 11 lie between?
if u know what the sqare root which is 3.32 than it will lie between 2 and 4
12. The variable in the expression 9x + 63 is ? * A. =
B. 9
C. x
D. 36
Answer:
C. x is the variable
Step-by-step explanation:
easy...
Julius bought F boxes of 24 plastic forks. He already had 39 plastic forks. Now, he has 135 plastic forks. How many boxes of plastic forks did Julius buy in all?
what is the problem??
Answer:
there is none
Step-by-step explanation:
19. Find x:
€ (17x-7)*
G
19
HELP W ALL 3 !!
Answer:
24
(17x-7)
x = 7 + 17
x = 24
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cuanto es 1+1
respuestas originales
gracias
Answer:
Step-by-step explanation:
It’s 2
Answer:
[tex]1 + 1 = 2[/tex]
[tex]espero \: haberte \: ayudado[/tex]
Can somebody plz help tell me how to find the people who surveyed like where do u find it? Thx!
WILL MARK BRAINLIEST WHOEVER CAN HELP WITH THIS :DDD
What is the length of 7.2 ft & 9.6ft
Answer:
16.8ft !
7.2 + 9.6 = 16.8 ft .
Answer:
12
Step-by-step explanation:
Using Pythagorean Theorem we know that
a² + b² = c²
7.2² + 9.6² = c²
51.84 + 92.16 = 144
Then find the square root of your c and you should get 12
__________________________
Or: 7.2 + 9.6 = 16.8 ft if that's what you mean
The radius of a sphere measures 2 units What is its surface area?
Surface area
1 square units
Answer:
A=50.265
Step-by-step explanation:
A
[tex]4\pi {r}^{2} [/tex]
[tex]4\pi {2}^{2} = 50.265482446[/tex]
Answer:
16
Step-by-step explanation:
The admission fee at an amusement park is $1.50 for children and $4 for adults. On a certain day, 235 people entered the park, and the admission fees collected totaled 690.00 dollars. How many children and how many adults were
admitted?
A map uses the scale 1.5 cm=25 mi. Two cities
are 190 miles apart. How far apart are the cities
on the map?
Answer: 11.4 cm
Step-by-step explanation:
190/25 = 7.6
7.6 x 1.5 = 11.4
Answer
the two cities are 11.4 cm apart on the map
Which point(s) lie on the line whose equation is - 4x + 5y - 12 = 8 Select all that apply. A (5, 0) В (- 2, 2.4) (8, 5) D (10, 12) E (0, 4)
Answer:
Options B, D and E
Step-by-step explanation:
Given equation is,
-4x + 5y - 12 = 8
-4x + 5y = 20
If a point given in the options lie on the line, point will satisfy the equation.
Option A.
For a point (5, 0),
-4(5) + 5(0) = 20
-20 = 20
False
Therefore, (5, 0) will not lie on the given line.
Option B
For (-2, 2.4)
-4(-2) + 5(2.4) = 20
8 + 12 = 20
20 = 20
True.
Therefore, (-2, 2.4) will lie on the given line
Option C
For (8, 5),
-4(8) + 5(5) = 20
-32 + 25 = 20
-7 = 20
False
Therefore, (8, 5) will not lie on the line.
Option D
For (10, 12)
-4(10) + 5(12) = 20
-40 + 60 = 20
20 = 20
True.
Therefore, (10, 12) will lie on the line.
Option E
For (0, 4)
-4(0) + 5(4) = 20
20 = 20
True.
Therefore, (0, 4) will lie on the line.
Options B, D and E are correct.
please solve this math problem very simple for points and if your correct you get brainly
math problem= 3x2x9+3/2-+3=?
Answer:
58 and 1/2
Step-by-step explanation:
Answer:
52.5
Step-by-step explanation:
54+3/2-3=51+3/2=52.5
Please answer correctly
GDE= 55º
Hope this helps!!
3. Here are diagrams that represent 0.137 and 0.284.
tenths
hundredths
thousandths
a. Use the diagram to find the value of. Explain your reasoning.
b. Calculate the sum vertically.
0.1 3 7
0.2 8 4
+
Im struggling a lot with these problems can anyone help and show the WORK please?
Answer:
Step-by-step explanation:
I'll give a couple answers so you get the gist of things.
All you have to do is substitute 1/2 for x and 3/4 for y.
Ex - 30. x × y = 1/2 × 3/4 = 3/8
What are the solutions to log6(x^2 + 8) = 1 +log6(x)?
X=-2 and x=-4
X=-1 and x = 8
X= 1 and X=-8
X= 2 and x=4
Answer:
D. x=2 and x=4
Step-by-step explanation:
Hope this helps!! Have a great day!! ❤
What is the volume of the prism?
hiii please help i’ll give brainliest:)
Answer:
I think the answer is monarchies(D).
Step-by-step explanation:
Answer:
monarchies
Step-by-step explanation: I found my answer in quiz let so if you want to find the flashcards just look up your question in goo gle to find it have a nice day : )
please no link because I can't access it when it's sent.please am asking no link
Answer:
x ≈ 1051.368672
Step-by-step explanation for #3:
[tex]tan(\frac{x}{12}) =24[/tex] Use tangent function because it relates to the opposite and adjacent sides of the triangle.
[tex]tan^{-1}(tan(\frac{x}{12}))=tan^{-1}(24)[/tex]
[tex]\frac{x}{12} = tan^{-1}(24)[/tex]
[tex]x = 12[tan^{-1}(24)][/tex]
x ≈ 1051.368672
If you have any more questions, feel free to ask and I'll answer them in the comments section under this answer. Please consider marking my answer as Brainliest, because it really helps me out.
Thanks!
can anyone explain how this is done.
Answer:
The answer is C. How many 3/4 -pound molds are in 1/3 pound of sand?
Answer:
The answer is C sorry I didnt answer earlier I had to do something and left brainly open-
The radius of the base of a cone is 4 inches. The slant height of the cone is
6 inches. Which is closest to the surface area of the cone?
F 75 sq in.
100 sq in.
H 126 sq in.
J 188 sq in.
The radius of the base of a cone is 4 inches. The slant height of the cone is 6 inches. Which is closest to the surface area of the cone ?
Answer:-Given:-[tex] \bullet [/tex] Radius (r) of the base of a cone is 4 inches.
[tex] \bullet [/tex] Slant height (l) of the cone is 6 inches.
To Find:-Which is closest to the surface area of the cone ?
Solution:-We know,
Formula of surface area of a cone is πr(r + l) sq. units.
Taking value of π = 3.14
So, Surface area of the cone = 3.14 × 4(4 + 6)
Surface area of the cone = 12.56 × 10
Surface area of the cone = 125.6 sq. inches.
[tex] \because [/tex] 126 sq. inches is closest to 125.6 sq. inches.
So, option (H) 126 sq. in is correct. [Answer]
if the dimensions of the box are 5.4 14.2 and 26.5 what is the volume
Answer:
just multiply these decimals ....
multiply... 5.4×14.2×26.5