Answer:

Step-by-step explanation:
Rewrite the system of equations as:

Subtract the second equation from the first to isolate
:

Plug in
into any of the equations above and solve for
:

Verify that the solution pair
works 
Therefore, the solution to this system of equations is:

Mr. Vella can build the wall in 4 days, however only works on it for 3 days. That means that he has completed 75% of the and is leaving 25% for his apprentice.
We need to figure out how long it takes the apprentice to build 25% of a wall. We know he can build 100% of a wall in 6 days, so dividing 6 days by 4 will give us our answer.
6/4 = 3/2 = 1.5 days
It took the apprentice 1.5 days to finish the wall.
-2 you just subtract the 3 by 1
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It should be noted that the z score for Thomas test grade is 0.237.
<h3>How to illustrate the information?</h3>
From the information, Thomas took a test in Social Studies and earned a 74.8 and there is the fact that all the students' test grades in the Social Studies class had a mean of 72.6 and a standard deviation of 9.3,
Therefore, the z score for Thomas test grade will be:
= Test score - Mean / Standard deviation
= 74.8 - 72.6 / 9.3
= 0.237.
Therefore, it should be noted that the z score for Thomas test grade is 0.237.
Learn more about standard deviation on:
brainly.com/question/12402189
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Thomas and Pablo began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Thomas took a test in Social Studies and earned a 74.8, and Pablo took a test in Science and earned a 64.1. Use the fact that all the students' test grades in the Social Studies class had a mean of 72.6 and a standard deviation of 9.3, and all the students' test grades in Science had a mean of 61.1 and a standard deviation of 9.8 to answer the following questions.
Calculate the z score for Thomas test grade.
Answer:
800 divided by 4 which is 200
Step-by-step explanation: