The answer will be 5.
|5-4|=1
Solution
For this case we can do the following:
11y - 3x = 18
16y -3x = 33
We can multiply the first equation by -1 and we got:
-11y +3x =-18
16y -3x = 33
_______________
16y -11y = 33-18
5y = 15
y= 15/5 = 3
And then solving for x we got
x = -(18 -11*3)/ 3= -15/3 = 5
Answer:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the lifetime for a TV of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability like this:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
Answer:




Solving for
we got
and replacing this we got:



And then the best option for this case would be:
b.csc x
Step-by-step explanation:
For this case we have the following expression given:

We know from math properties that the definition for cot is 
If we use this definition we got:


Now we can use the following identity:

Solving for
we got
and replacing this we got:



And then the best option for this case would be:
b.csc x
The denominator is the one on the bottom so 9 is the denominator the top is the numerator