Answer:
(3+1)X 6
Step-by-step explanation:
that means 4x6
First, note that

is always positive (except for x=0), so

must be always negative.
Thus, the only plausible graphs are 1 and 3 since they are below the x-axis.
Now,

and

are only defined for x≥0, because only for these x'es we can take the square root.
Note that the third graph has domain (-infinity, 0], so it is not the right one, while 1 is ok.
Answer: first graph
Hello!
2.x^2 - 1 = 2.3^2 - 1 = 2.9 - 1 = 18-1 = 17
Good luck!
Step-by-step explanation:
hope you can understand
Answer:
The mean of the total repair time is 150 minutes.
The variance of the total repair time is 725 minutes^2.
Step-by-step explanation:
To solve this problem, we have to use the properties of the mean and the variance. Our random variable is the sum of 3 normal variables.
In the case, for the mean, we have that the mean of the sum of 3 normal variables is equal to the sum of the mean of the 3 variables:

For the variance, we apply the property for the sum of independent variables (the correlation between the variables is 0):
