Answer:
If your install Bratleby on your device, It will help you with this. But you will have to put in an email. and it will give 10 questions to answer for free. Sorry that I cannot help you with this.
Step-by-step explanation:
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
I got 7 if you are trying to look for the value of x than you multiply the bottom by two to have the y's equal. It should be
3x+2y=25
12x-2y=80
Since the twos mark each other out it would be
3x=25
12x=80
You add the top and bottom so it becomes one like this
15x=105
Divide 15 on both sides and it should give you 7.
X=7
Answer:
C
Step-by-step explanation:
Given y ∝ then the equation relating them is
y = ← k is the constant of variation
To find k use the condition y = - 2 when x = 14 , then
- 2 = ( multiply both sides by 14 )
- 28 = k
y = - ← equation of variation
The value of x in the equation is 23.
<h3>How to solve equation?</h3>
46 / x = 2
The equation above have one solution because the value of x is a single value.
46 / x = 2
cross multiply
2x = 46
divide both sides by 2
2x / 2 = 46 / 2
x = 23
A value of x that makes an equation true is 23, which when substituted into the equation and simplified makes the equation turn into x = 23.
A value of x that makes an equation false is 46, which when substituted into the equation and simplified makes the equation turn into x = 46.
learn more on equation here: brainly.com/question/24964043
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