Answer: First option.
Step-by-step explanation:
You know that the product obtained by multiplying a binomial and a trinomial is:

Then, in order to simplify this product, it is necessary to add the like terms.
Therefore, the expression that is equivalent to this product after it has been fully simplified is:

You can observe that this matches with the first option.
Answer:
A is correct
Step-by-step explanation:
Answer:
xy
Step-by-step explanation:
x + y = xy because of the addition sign
ANSWER: The statistical procedure that should be performed is REGRESSION.
Step-by-step explanation: Regression is a statistical procedure that is used to estimate the relationship between an independent variable and a dependent variable using their mean values.
The independent variable in this case is the hours each student spend in studying, while the dependent variable is the students grade.
Since the researcher wants to determine if the hours a student spend in studying maths and science has any significant effect on their grades. The researcher should use regression, because it will show if the two variables are related and how it relates, by showing how far the points are from the trend lines of the graph.