Here's the question you clicked on:

## ilovenyc Group Title Which of the following inequalities matches the graph? (see attached photo) A y _>_3x - 5 B y < 3x - 5 C y < 1/3x - 5 D The correct inequality is not listed. one year ago one year ago

• This Question is Closed
1. ilovenyc Group Title

2. srossd Group Title

Alright, so lets pick up where we left off. Can you find two points on the line?

3. ilovenyc Group Title

(4,7)

4. srossd Group Title

Yup, that's one, good job.

5. srossd Group Title

@ilovenyc Can you find another one?

6. ilovenyc Group Title

(2,8)

7. srossd Group Title

@ilovenyc Well, go over to 2 on the x axis, and then go up until you hit the line. What y are you at? That's how you get a point.

8. ilovenyc Group Title

(2,0)?

9. srossd Group Title

@ilovenyc Not quite, although the drawing isn't too great. (2,1) is on the line.

10. srossd Group Title

Do you see how that works?

11. ilovenyc Group Title

YES

12. srossd Group Title

Great! So now, do you remember how to find the slope?

13. ilovenyc Group Title

To find the slope m of the line segment joining the points, use the slope formula

14. srossd Group Title

Right, so try doing that with (2,1) and (4,7)

15. srossd Group Title

@ilovenyc Making any progress, or do you need some help?

16. ilovenyc Group Title

need some help do i add those both together?

17. srossd Group Title

Not quite, it's more of a subtraction. Here's the slope formula: $\frac{y_2-y_1}{x_2-x_1} \; \; \; x_1 = 2 \; \; \; x_2 = 4 \; \; \; y_1=1 \; \; \; y_2=7$

18. srossd Group Title

@ilovenyc So see if you can use that to find the slope. I'll be back in just a little bit.

19. ilovenyc Group Title

@srossd so i need to subtract that

20. srossd Group Title

@ilovenyc Just use that formula I wrote, plug in the numbers. And now I'll be back in a little bit :).

21. ilovenyc Group Title

is the answer 13?

22. srossd Group Title

No, here's another hint: $\frac{7-1}{4-2}$

23. srossd Group Title

And ok, now I'm actually leaving for a little bit.

24. srossd Group Title

Just a few minutes, though.

25. srossd Group Title

@ilovenyc Alright, I'm back now. So did you get the slope from that?

26. ilovenyc Group Title

6,and 2

27. srossd Group Title

Well, 6 divided by 2.

28. srossd Group Title

So the slope ends up being 3.

29. srossd Group Title

@ilovenyc So now you know that the line will be y=3x+b. So plug in x = 0 to that, and you'll be y=b. So look at the graph, and go to the point where x=0. Find what y is.

30. srossd Group Title

|dw:1356749491751:dw|

31. ilovenyc Group Title

-4?

32. srossd Group Title

The drawing is bad again, it's actually -5. But close enough that I'm pretty sure you get it.

33. srossd Group Title

So if your equation was y=3x+b, and b=-5, what's your final equation?

34. ilovenyc Group Title

2 = 3*(-4) + b?

35. srossd Group Title

No, no - just plug in the value of b (-5) to y=3x+b. The x and y should stay.

36. ilovenyc Group Title

okay

37. srossd Group Title

@ilovenyc Do you understand, or do you need some help?

38. ilovenyc Group Title

need some help

39. srossd Group Title

Ok, so you solved for b, so just put it where b was. The equation comes out to be y=3x-5.

40. srossd Group Title

Do you see how that works, plugging in -5 for b?

41. ilovenyc Group Title

so B is the answer

42. srossd Group Title

Actually, it's A, since everything above the line is shaded. B would be the opposite shading.

43. ilovenyc Group Title

oh okay

44. srossd Group Title

But still, good job!

45. srossd Group Title

And again, sorry for elongating this so much - I just wanted to make sure you understand how to do it.

46. srossd Group Title

@ilovenyc So do you feel like you have a good grasp on how to do this type of problem now?

47. ilovenyc Group Title

@srossd i think so...

48. srossd Group Title

Alright, good. I can make up another one for you to try if you want.

49. ilovenyc Group Title

well i have more problems that i need to do on my homework

50. srossd Group Title

Oh, ok. Need help with those?

51. ilovenyc Group Title

yes

52. srossd Group Title

Ok, want to post a new problem?

53. srossd Group Title

@ilovenyc I'll be on the lookout for a new post.