A:
An independent variable could be how long she works. (Well it's not really independent I guess... Sorta depends.)
A dependent variable could be how much money she makes, depending on how long she works.
B:
Umm, like:
(1, 7)
If 1 was how many hours she worked and $7 is how much money she made, and therefore x would be how many hours she worked and y would be how much total money she made.
(2, 14)
(3, 21)
C: An equation would be 7x = y.
Answer:
k = 3
Step-by-step explanation:
We have the distance formula: 
. We can plug in 
= d, x2 = 6, x1=2, y2 = 7, y1 = k.
Then, we can solve the question using some algebra to find that k = 3.
Edit: Here is a step by step:
X=12.5
If the perimeter is 90
90=3x+3x+15
Combine like terms
90=6x+15
Subtracts 15 from both sides
75=6x
Divide by six to get x by itself
12.5=x
Does this help?
12 + 0.35X = 20.05
12 + 0.35X - 12 = 20.05 - 12
0.35X = 8.05
0.35X/0.35 = 8.05/0.35
X = 23
Hope this helps!!
