Answer:
The expression which will result in difference of two squares is:
(–7x + 4)·(–7x – 4)
Step-by-step explanation:
We know that the formula of the type:
(a-b)(a+b)=a²-b²
i.e. it is a difference of two square quantities. (a^2 and b^2)
since,
a= -7x , b=4
(-7x+4)(-7x-4)= (-7x)² - (4)²
=(7x)² - 4²
So the expression is a difference of two square quantities:
(7x)² and (4)²
Hence the answer is (–7x + 4)·(–7x – 4)....
Answer:
14.69% probability that defect length is at most 20 mm
Step-by-step explanation:
When the distribution is normal, we use 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.
In this question, we have that:

What is the probability that defect length is at most 20 mm
This is the pvalue of Z when X = 20. So



has a pvalue of 0.1469
14.69% probability that defect length is at most 20 mm
Answer:
Im not sure what it is to do but the answer i got was -886.6
C adding a number to itself