9514 1404 393
Answer:
21
Step-by-step explanation:
Rearranging the given ratio, we can find the ratio of boys to the total.
boys : (boys +girls) = 7 : (7+8) = 7 : 15
Then the number of boys is ...
(7/15)(45) = 21
There are 21 boys in the classroom.
Top:
36 + 2(3)
36 + 6
☆42
bottom:
36 - 4(2)(3)
36 - 24
☆12
- We are to find the time (number of minutes) is would take for 23 mg of the substance to be remaining.
- The formula for time is written as:
t = [t1/2 x In(Nt/No)] / In 2
where:
t1/2 = Half life = 4 minutes
No = Initial quantity of the sample = 90 mg
Nt = Amount of the sample left = 23 mg
t = time elapsed = ?
Hence,
t = [4 x In (23/90)] / -In 2
t = 7.8731645610906 minutes
Approximately to the nearest hundredth = 7.87 minutes
Therefore, there will be 23mg of substance remaining after 7.87 minutes.
To learn more, visit the link below:
brainly.com/question/16624562
Answer:
<em>We disagree with Zach and Delia and agree with Alicia</em>
Step-by-step explanation:
The domain of a function is the set of values of the independent variable that the function can take according to given rules or restrictions.
The range is the set of values the dependent variable can take for every possible value of the domain.
The graph shows a continuous line representing the values of the function. We must take a careful look to the values of x (horizontal axis) where the function exists. It can be done by drawing an imaginary vertical line passing through the value of x. If that line touches the graph of the function, it belongs to the domain. It's clear that every value of x between -5 and 3 (both inclusive because there are solid dots in the extremes) belong to the domain:
Domain: 
The range is obtained in a similar way as the domain, but the imaginary lines must be horizontal. That gives us the values of y range from -7 to 5 both inclusive:
Range:

Thus we disagree with Zach and Delia and agree with Alicia