An element with mass 780 grams decays by 17.1% per minute. How much of the element is remaining after 19 minutes to the nearest
1 answer:
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Answer:
B
Step-by-step explanation:
In order to get the same denominator, we need to multiply the second fraction by (b+2) in the numerator and denominator.
We will end up in something like this :
I just timed the second fraction by b+ 2 and then i added them together.
Therefore, we will get
now factoring the numerator we will end like this
we will then end up with the answer.
Hope this helps.
Answer:
Step-by-step explanation:
Given that in a sample of 800 U.S. adults, 199 think that most celebrities are good role models. Two Two U.S. adults are selected at random from the population of all U.S. adults without replacement.
In 800 adults 199 are favourable and remaining 601 are against.
a) The probability that both adults think most celebrities are good role models is ________= Prob of selecting both from 199
=
=0.062
b) The probability that neither adult thinks most celebrities are good role models is _______=P(both selecting from 601)
=
=0.564
c) The probability that at least one of the two adults thinks most celebrities are good role models ______
=1-Prob that neither thinks
= 1- 0.564
= 0.436
Answer:
The Law of Cosine : cos C =
Step-by-step explanation:
See the figure to understand the proof :
Let A Triangle ABC with sides a,b,c,
Draw a perpendicular on base AC of height H meet at point D
Divide base length b as AD = x -b and CD = x
By Pythagoras Theorem
In Triangle BDC And In Triangle BDA
a² = h² + x² ( 1 ) c² = h² + (x-b)²
c² = h² + x² + b² - 2xb ...(. 2)
From above eq 1 and 2
c² = (a² - x²) + x² + b² - 2xb
or, c² = a² + b² - 2xb .....(3)
Again in ΔBDC
cos C =
Or, cos C =
∴ x= a cos C
Now put ht value of x in eq 3
I.e, c² = a² + b² - 2ab cos C
Hence , cos C = Proved Answer
