One hundred grams of radium are stored in a container. The amount RR (in grams) of radium present after tt years can be modeled by R=100e−0.00043tR=100e−0.00043t. After how many years will only 5 grams of radium be present? Round your answer to the nearest whole year.
Answer:
6967 years
Step-by-step explanation:
Given the exponential function :
R=100e−0.00043t
Time = t in years
R = final amount
Number of years in which only 5 grams of radium will be present :
R = 5
Plugging into our formula :
5 = 100 * e^−0.00043t
5 / 100 = e^−0.00043t
0.05 = e^−0.00043t
Take the In of both sides
−2.995732 = - 0.00043t
t = −2.995732 / - 0.00043t
t = 6966.819
t = 6966.819 years
t = about 6967 years
For the expression 6 + y - 3, determine the coefficient for the variable term.
A -3 B 0 C 1 D 6
Explanation:
Think of 6 + y - 3 as 6 + 1y - 3
y and 1y are the same thing because 1 times any number is that same number.
The coefficient is the number to the left of the variable, so the coefficient is 1.
Please help me with this ASAP
In the morning, a farm worker packed 3 pints of strawberries every 4 minutes. In the afternoon, he packed 2 pints of strawberries every 3 minutes. What was the difference between the morning and afternoon pack rates, in pints per hour?
A 5
B10
C40
D45
Answer:
A 5
Step-by-step explanation:
60 mins = 1 hour
60 divided by 4 is 15
60 divided by 3 is 20
15 times 3 is 45
20 times 2 is 40
45 - 40 is 5
If the resistance in an electrical cirouit is
held constant, the amount of current
flowing through the circuit is directly
proportional to the amount of voltage
applied to the circuit. When 12v are applied
to a circuit, 240 mA of orrent flow
through the circuit. Find the new current if
the voltage is increased to 14 volts.
:
(2x – Зу = 18
(2x + y = 2
Answer:
2x = 2 × 12 = 24 24 =2x 24-6=18
3y = 3 × 2 = 6 6 =3y
2x = 2×1 = 2 2 =2x 2+0=2
y = 0 0 = y
Step-by-step explanation:
I'm not sure how the question is mentioned in the test but from my point of view I got this not sure how the it is explained in your nest im only 11 so yeh. sos if its wrong
Answer:
y = -4
x = 3
Step-by-step explanation:
I will be using the elimination method to solve this:
Begin by times -1 to the bottom equation.
[tex]2x-3y=18[/tex]
[tex]-2x-y=-2[/tex]
Add them together
[tex]0x-4y=16[/tex]
ignore the 0x and divide -4 to both sides
[tex]\frac{-4y}{-4} =\frac{16}{-4}[/tex]
y = -4
Plug y back into one of the two original equations
[tex]2x-3(-4)=18[/tex]
multiply -3 and -4 to get +12
[tex]2x+12=18[/tex]
subtract 12 to both sides
[tex]2x=6[/tex]
divide by 2 to both sides
x = 3
Sandy took a boat ride down the Guadalupe River. The boat averaged 18 miles per hour. If the trip took 4 1/2 hour, how far down the river did Sandy ride?
Answer:
81 miles
Step-by-step explanation:
18x4=72 and then you have to add the 1/2 and 1/2 of 18 is 9 so you add 72+9=81 to get the answer. Hope this helps! <3
The rectangle is 16 inches by 25 inches. If the scale is 4 in :5 ft what is the length and width of the rectangle in feet.
Answer:
The length and width of the rectangle are 20 feet and 31.25 feet, respectively.
Step-by-step explanation:
Let the scale be [tex]4\,in\,:\,5\,ft[/tex] and the dimensions of the rectangle being 4 inches and 5 inches, respectively. The scale ([tex]r[/tex]), measured in inches per feet, is equivalent to the following rational number:
[tex]r = \frac{4\,in}{5\,ft}[/tex]
We can convert each length by dividing it by scale factor. That is:
Length
[tex]l' = \frac{16\,in}{\frac{4\,in}{5\,ft} }[/tex]
[tex]l' = 20\,ft[/tex]
Width
[tex]w' = \frac{25\,in}{\frac{4\,in}{5\,ft} }[/tex]
[tex]w' = 31.25\,ft[/tex]
The length and width of the rectangle are 20 feet and 31.25 feet, respectively.
A.42.6 square units
B. 128 square units
C. 32 square units
D. 64 square units
Answer:
Step-by-step explanation:
D. 64 square units
subtract x^2 - 2x - 6 from -6x + 5
Answer:
x^2+4x-11
Step-by-step explanation:
x^2 - 2x - 6 - (-6x + 5)
x^2-2x-6 +6x - 5
x^2 +4x -11
A(n) _____ inequality is an inequality involving a quadratic expression.
A. Quadratic
B. Linear
C. Absolute value
D. Rational
Answer:
Step-by-step explanation:
A.Quadratic
Alexandra is going to a carnival that has games and rides. Each game costs $3 and
each ride costs $4.50. Alexandra spent $54 altogether at the carnival and the number
of rides she went on is 7 more than the number of games she played. Graphically
solve a system of equations in order to determine the number of games Alexandra
played, 2, and the number of rides Alexandra went on, y.
PLEASE ANSWER ASAP
Answer:
Game =$6 and ride=$9, to solve is 3x+4y=54
x+y=15
Step-by-step explanation:
;)
Write the equation of the line that passes through the points (0,7) and (-4, -9).
Put your answer in fully reduced point-slope form, unless it is a vertical or horizontal
line.
y=4x+7
First we need to figure out the slope. We can do that using the equation (y2-y1)/(x2-x1). Substitute your numbers in for the xs and ys:
(-9-7)/(-4-0)=
-16/-4=
4
Now that we have the slope, we can figure out the intercept by using the equation y=mx+b and substituting one of the points in for x and y, the slope in for m, and solving for b.
I’m going to use (0,7) as it will be faster:
7=4(0)+b
7=0+b
7=b
The full equation will then be:
y=4x+7
I need the x and y value
I did it and I got 26 got both, but I’m not sure.
Answer:
x=26
y=116
Step-by-step explanation:
Answer:
Step-by-step explanation:
x8 y5
What are the points Please ASAP
Answer:
(0,1)
(0,-3)
(-2.5.-3)
Step-by-step explanation:
pls give me brainliest
:)
What is the probability that the dart will hit a spot in the shaded square
Answer:
B: 1/6
Step-by-step explanation:
3 divided by 18 = 3 x 1/18 = 3/18 = 1/6 (simplified)
You may use a calculator for this item.
To be a member at Salls gym, there is a one-time sign-up fee plus a monthly fee for each month of membership. The
table shows the total cost to be a member of the gym for different numbers of months.
Number of Months
3
Total Cost
$53.97
$77.94
$125.88
6
12
Create a function that gives the total cost, C. in dollars, to be a member of the gym given the number of months, m, of
membership
Enter your function in the space provided.
+
х
-
. 18
1
=
%
+ B
get rr
Answer:77.94
Step-by-step explanation:
My classroom is 12 feet by 16 feet. What is the area of my classroom? Make sure you label your answer correctly with your answer.
Answer:
[tex]192 \: sq {}^{2} [/tex]
Step-by-step explanation:
To find area, multiple the length by the width. In this case, the length is [tex]16[/tex] and the width is [tex]12[/tex].
[tex]12×16=192[/tex]
7.1 divided by 312.755
answer 0.0227014756
Step-by-step explanation:
or if you meant 312.775/7.1 it's 44.0528169
Can somebody help me please
A racecar driver completes a race 30 laps in 15 minutes at a constant speed. what is the driver's speed?
Answer:
200 mph/321 km/h if the track is 1 mile long and 100 mph/160 km/h if the track is 2 miles long
Step-by-step explanation:
Can someone help me please
Everything we see and touch is made of ______.
Answer:
chemicals
Step-by-step explanation: everything we see and touch is made up of a mixture of chemicals
Consider the graph of f(x) below. The graph contains the points (0, 1) and (5, 4).
Write the equation of f(x), and classify the function as linear, quadratic, cubic, exponential, power, or logarithmic.
Answer:
f(x)=x+3
Step-by-step explanation:
hope this helps
Help i dont know the answer
Answer:
25
Step-by-step explanation:
In her first 5 days, she reads 80 pages. That means that per day, she reads 16 pages. Then, she had 400 pages left, since 480-80 = 400.
So, you divide 400/16 = 25 days.
Clayton picks an integer (from 1 to 20) at random. Which event has a probability that is closest to 0? picking a number greater than 6 picking a number less than 12 picking an even number picking a prime number
Answer:
picking a prime number
Step-by-step explanation:
from 1 - 20 : 20
>6 : 15
<12 : 11
even number: 10
Prime: (2,3,5,7,11,13,17,19) 8
PLEASE ANSWER NOW FOR A TEST
Triangle ABC is similar to triangle TNW. Side BC corresponds to side NW. The perimeter of triangle ABC = 13.46. What it the perimeter of triangle TNW? A. 3.365
B. 4.24
C. 10.28
D.13.46
How many grams are there in 2 ounces?
Answer:
Step-by-step explanation:
1 ounce = 28.3 gm
2 ounce =x
x =2*28.3
x = 56.6 gm
solve this please
log(4x+16)=2
Answer:
X = -3.5
Step-by-step explanation:
Answer:
-7/2
Step-by-step explanation:
4x+16=2
-16 -16
4x= 2-16
4x=-14
/4 /4
x= -7/2
YeS mOrE 9Th GrAdE mAtH (question for smart people)
Answer:
A. 4x+13
Step-by-step explanation:
distribute the 4
(4x+20) -7
4x+13
Answer:
A
Step-by-step explanation: