Answer:

Step-by-step explanation:
Given:
The expression to expand is given as:

Let us expand the first two binomials of the given expression using FOIL method.
The FOIL method states that:


Now, let us multiply the result with the remaining binomial. Multiplying each term of the trinomial with each term of the binomial, we get:

Therefore, the equivalent expression after expanding is given as:

Answer: Choice A
The number line graph is visually showing every number that is 19 or smaller; hence 
Note the use of a closed or filled in circle at the endpoint (in contrast to an open circle). This indicates we are including the endpoint 19 as part of the solution set, and that's why we go for "or equal to" as part of the inequality sign.
The larger the number of simulations the more likely are the results to be closest to those predicted by the probability theory.
When large number of simulations are run, some results might be higher than the results of probability theory, some results might be lower than the results of the probability theory and some might be exactly the same. So the average of all these results will be close to the results of Probability Theory. Thus, more the number of simulations, greater is the chance that the results are closer to those of simulation theory.
Thus, option A will be the correct answer.
Answer:
Keenan's z-score was of 0.61.
Rachel's z-score was of 0.81.
Step-by-step explanation:
Z-score:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Keenan scored 80 points on an exam that had a mean score of 77 points and a standard deviation of 4.9 points.
This means that 
So



Keenan's z-score was of 0.61.
Rachel scored 78 points on an exam that had a mean score of 75 points and a standard deviation of 3.7 points.
This means that
. So



Rachel's z-score was of 0.81.
Answer:
△PQR and △RST are not similar.
Step-by-step explanation:
In triangle △PQR, two known interior angles are 34° and 80°. So the measure of third angle is

In triangle △RST, two known interior angles are 24° and 90°.

Two triangles are similar if their corresponding angles are same and the corresponding sides are proportional.
Since the angles of △PQR and △RST are not same, therefore we can say that the △PQR and △RST are not similar.