C. The way the sample was chosen may overrepresent or underrepresent students taking certain language classes.
The samples he chose may not be a representative sample because the number of students per foreign language class may not be the same. Since classes have different numbers of students, one may have a very large number of students while another may have only a few. Taking equal number of students per class is not a representative sample because it doesn't represent the students correctly.
Let x represent number of bracelets and y represent number of necklaces.
We have been given that a jeweler made 7 more necklaces than bracelets. This means that number of necklaces will be
. We can represent this information in an equation as:

We have been given that the amount of gold in each bracelet is 6 grams, so amount used for x bracelets would be
grams.
We are also told that the amount of gold in each necklace is 16 grams, so amount used for y necklaces would be
grams.
Since the jeweler used 178 grams of gold, so we will equate the amount of gold used in x bracelets and y necklaces with 178 as:

Therefore, our required system of equations would be:


Answer:

Step-by-step explanation:
Given

Required
Determine the reduction when paid is reduced to 49 weeks
First, we need to determine the weekly pay


Next, is to determine the pay for 49 weeks;



Subtract the 49 week pay from 52 weeks pay to get the payment reduction;


Answer:
A
Step-by-step explanation:
(2m-n) is a factor of 4(2m-n)
Answer:
<h2>Cubing both sides of an equation is reversible.</h2>
Step-by-step explanation:
Squaring both sides of an equation is irreversible, because the square power of negative number gives a positive result, but you can't have a negative base with a positive number, given that the square root of a negative number doesn't exist for real numbers.
In case of cubic powers, this action is reversible, because the cubic root of a negative number is also a negative number. For example
![\sqrt[3]{x} =-1](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7Bx%7D%20%3D-1)
We cube both sides
![(\sqrt[3]{x} )^{3} =(-1)^{3} \\x=-1](https://tex.z-dn.net/?f=%28%5Csqrt%5B3%5D%7Bx%7D%20%29%5E%7B3%7D%20%3D%28-1%29%5E%7B3%7D%20%5C%5Cx%3D-1)
If we want to reverse the equation to the beginning, we can do it, using a cubic root on each side
![\sqrt[3]{x}=\sqrt[3]{-1} \\\sqrt[3]{x}=-1](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7Bx%7D%3D%5Csqrt%5B3%5D%7B-1%7D%20%5C%5C%5Csqrt%5B3%5D%7Bx%7D%3D-1)
There you have it, cubing both sides of an equation is reversible.