For this case we have that by definition, the equation of a line in the slope-intersection form is:

Where:
m: It is the slope
b: It is the cut point with the y axis
The slope is: 
Thus, the equation is of the form:

We substitute the given point and find "b":

Finally, the equation is:

Answer:

9/10 is the answer. Basic elementary math
Miles, who makes cash contributions to charities.
Answer:

So then the correct answer is B. $200.
Step-by-step explanation:
Notation
Let X be the average contribution size before John makes his contribution.
Let Y be the total contribution size before John makes his contribution.
Let Z be John's contribution.
We know that for this case $ 75 represent the original average amount before the contribution with 50% increase so we can set up the following equation in order to find the original average amount

And solvong for X we got:

Now we can find the total contribution before the donation with the following proportion:


And then with the formula of average taking in count the 6 values we can find the size of donation Z like this:



So then the correct answer is B. $200.