Answer:
He multiplyed 3x8 and 5x8 when it should be 3x8 and 5x1 because you but 1 under the 8 to make it into a fraction.
Step-by-step explanation:
<span>An obtuse angle is any angle greater than 90 degrees and less than 180 degrees.
We have 2 angles, one of x degrees, and the other of 2x degrees. Their sum is 3x degrees, and this must be in the range that defines an obtuse angle. Therefore:
90 < 3x < 180, and dividing all by 3, we get
30 < x < 60, and multiplying by 2 gives
60 < 2x < 120, which the range of possible degrees for the larger angle.</span>
Answer:
(- 2, - 9 )
Step-by-step explanation:
The axis of symmetry passes through the vertex of the parabola.
Thus the x- coordinate of the vertex is x = - 2
To find y substitute x = - 2 into f(x)
f(- 2) = (- 2)² + 4(- 2) - 5 = 4 - 8 - 5 = - 9
Vertex = (- 2, - 9 )
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):
