The line of symmetry is 1
A zero in front of the x would make this a difference of two perfect squares. All of the other option would interfere by adding another term.
Answer:
its d
Step-by-step explanation:
the options can be eliminated by using common sense.
The value of z-score for a score that is three standard deviations above the mean is 3.
In this question,
A z-score measures exactly how many standard deviations a data point is above or below the mean. It allows us to calculate the probability of a score occurring within our normal distribution and enables us to compare two scores that are from different normal distributions.
Let x be the score
let μ be the mean and
let σ be the standard deviations
Now, x = μ + 3σ
The formula of z-score is

⇒ 
⇒ 
⇒ 
Hence we can conclude that the value of z-score for a score that is three standard deviations above the mean is 3.
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Because when you subtract a negative number the signs cancel out and become and addition problems