Answer:
x=5
Step-by-step explanation:
7x - 4y = 23 and x + y = 8
Multiply the second equation by 4
4x + 4y = 32
Add this to the first equation
7x - 4y = 23
4x + 4y = 32
------------------------
11x = 55
Divide each side by 11
11x/11 = 55/11
x = 5
10.31991744 meters per second
Answer:
Try solving 6(n-5)-2.
Step-by-step explanation:
I believe this can be set up as 6(n-5)-2. The difference of a number and five can be represented by n-5. If this needs to be multiplied by 6 (hence 6 times), it would become 6(n-5). Two less than that is represented by -2. Thus, two less than six times the difference of a number and five is 6(n-5) -2, which, when n=9 is plugged in, looks like 6(9-5) -2. Follow PEMDAS from there.
Answer:
a) The mean is 
b) The standard deviation is 
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
The probability a student selected at random takes at least 55.50 minutes to complete the examination equals 0.6915.
This means that when X = 55.5, Z has a pvalue of 1 - 0.6915 = 0.3085. This means that when 
So




The probability a student selected at random takes no more than 71.52 minutes to complete the examination equals 0.8997.
This means that when X = 71.52, Z has a pvalue of 0.8997. This means that when 
So




Since we also have that 





Question
The mean is 
The standard deviation is 
By definition of absolute value, you have

or more simply,

On their own, each piece is differentiable over their respective domains, except at the point where they split off.
For <em>x</em> > -1, we have
(<em>x</em> + 1)<em>'</em> = 1
while for <em>x</em> < -1,
(-<em>x</em> - 1)<em>'</em> = -1
More concisely,

Note the strict inequalities in the definition of <em>f '(x)</em>.
In order for <em>f(x)</em> to be differentiable at <em>x</em> = -1, the derivative <em>f '(x)</em> must be continuous at <em>x</em> = -1. But this is not the case, because the limits from either side of <em>x</em> = -1 for the derivative do not match:


All this to say that <em>f(x)</em> is differentiable everywhere on its domain, <em>except</em> at the point <em>x</em> = -1.