Answer:
21.68 minutes ≈ 21.7 minutes
Step-by-step explanation:
Given:

Initial temperature
T = 100°C
Final temperature = 60°C
Temperature after (t = 3 minutes) = 90°C
Now,
using the given equation

at T = 90°C and t = 3 minutes


or

taking the natural log both sides, we get
3k = 
or
3k = -0.2876
or
k = -0.09589
Therefore,
substituting k in 1 for time at temperature, T = 65°C

or

or

or

taking the natural log both the sides, we get
( -0.09589)t = ln(0.125)
or
( -0.09589)t = -2.0794
or
t = 21.68 minutes ≈ 21.7 minutes
Answer:
9/2
Step-by-step explanation:
in order to find the fraction form of 4.5... we need to set a denominator. The denominator has to be greater than 1 because we 4.5 is not a whole number...
we want the simplest denominator in the end... so we'll pick 2 for a denominator and change it if it doesn't work in the end...
now that we know the denominator... we have to make the numerator 4 times larger than the denominator (2)... when we do this... we get 8/2
since we made the numerator 4 times larger than the denominator... we know that 8/2 is the same as 4
now we need to find the remaining 1/2
this can be done by simply adding 1/2 to 8/2 (which is easily done thanks to a common denominator)
Since 9/2 cannot be simplified any further... it is our final answer
Answer: she combined the constants incorrectly in the last step.... i just got it right on the test
Answer:
Step-by-step explanation:
A question on a math quiz asks, "What is 175% of 72?" Petra calculates 12.6 as the answer. Is this a reasonable answer? Explain