Question

I'm doing Algebra II virtual school. I've asked my teacher and tutors about these types of question and they cannot provide a sufficient answer. Please someone help me figure this out I would greatly appreciate it. A sample problem or hints would be nice, I do not want the answer I simply want to know how to approach the problem.

The resistance (R) in a wire increases when the length of the wire (L) increases. Write the correct equation for this scenario, and solve for when the length is 1.

Length I Resistance
------------
10 I 2
-------
15 I 3

Answer 1

R increases as L increases, so R is dependent on L.
R → dependent variable
L → independent variable
You can write the given data as points in the form (L, R).
The points are (10, 2) and (15, 3)

Answer 2

You can use two points to write the equation of the line. Start by finding the slope. Do you know the formula and how to use it?

Answer 3

yes y2-y1/x2-x1

Answer 4

right. What did you get for slope?

Answer 5

1/5

Answer 6

so use point slope then solve for b by pluging in a point?

Answer 7

yes.

Answer 8

here maybe you will understand my confusion if I give you the possible answers

Answer 9

because I did that and my answers aren't remotely close to the possible answers.. Ty for your help btw I really appreciate it :)

Answer 10

R = 20 over L; R = 20

R = .2L; R = 5

R = .2L; R = .2

R = 20 over L; R = 5

Answer 11

what did you get for your b?

Answer 12

1/5 is the same as 0.2, so the slope is correct

Answer 13

8

Answer 14

not sure where you went wrong. b should be 0

Answer 15

oh now I see i added instead of subtracting in one of my steps lol

Answer 16

so just plug 1 into y=.2x and I get the correct answer?

Answer 17

yes, plug 1 in for y

Answer 18

Got it ! Thank you so much!! :).. Ima have to tell my teachers that peachpi is a better teacher then them haha

Answer 19

lol. wait until after you're done with the class ;)