1. itsjustme_lol

a.) y = - 2x - 2 b.)y = - 3x - 2 c.)y = - 2x - 4 d.)y = - 3x - 4

2. binarymimic

looks like a slope of -3 and y intercept of -4

3. nitz

i am not able to see the points clearly............can u just repost it by zooming

4. itsjustme_lol

yes hang on.

5. binarymimic

6. itsjustme_lol

well come to think of it..i cant see the points either

7. itsjustme_lol

thanks @binarymimic, i cant even see the points on the original picture on my screen

8. whpalmer4

Look at the graph to find points where you can see the exact values. (-2,2) and (-1,-1) are two such points. Difference of 1 in the x values gives a difference of -3 in the y values, so the slope is -3 (y goes down as x goes up). The y intercept is just the value of y where the line crosses the y axis, and that is -4. the formula for the line in slope intercept form is y = mx + b where m is slope and b is y-intercept, so y = -3x -4, choice d).

9. nitz

ya...........for sure its d firstly the y -intercept is -4 and secondly the graph passes through (-2,2)

10. itsjustme_lol

can you confirm my answer on my next one?

11. itsjustme_lol

What is the slope of a line perpendicular to the line in this graph? i got -1/3

12. binarymimic

i think you forgot to take the reciprocal of it

13. itsjustme_lol

ohh so it would just be 1/3 instead of -1/3?

14. whpalmer4

Slope of a perpendicular line will be -1/m. m in this graph is 1/3 (3 units to the right for x to make 1 unit up for y), so the correct answer would be -1/(1/3) or -3. you want the line to be going steeply down from left to right

15. whpalmer4

move 1 unit right in x, down 3 in y

16. binarymimic

the reciprocal of a # is what you get when you take 1 divided by the #

17. itsjustme_lol

ohhh so -3..i see. sorry! lol

18. binarymimic

yeah

19. whpalmer4

always good to mark off a pair of points with the new equation to make sure the line is what you expect!

20. whpalmer4

so easy to make arithmetic or sign errors...

21. itsjustme_lol

ok i have one more question about graphing..do you guys want me to post in as a new question or just post it here? aand thankyou so much! and yes, I tend to make sign errors a lot lol

22. itsjustme_lol

i think i have the answer to my question..just want to get a second thought on it

23. whpalmer4

fire away

24. itsjustme_lol

Given the point (-4, 2) and a slope of -1

25. itsjustme_lol

26. binarymimic

did you draw that?

27. itsjustme_lol

heres the other ones that i had to choose from

28. itsjustme_lol

noo. too bad i still cant see the points..idk why they would put it soo small

29. whpalmer4

If the slope is -1, then it should move one point down and one to the right, like in aaa.gif

30. binarymimic

look carefully at the choices. which one has (-4, 2) as a point, and a slope of -1

31. itsjustme_lol

is it safe to choose ccc.gif or no?

32. whpalmer4

They've all got (-4,2) as a point. only aaa.gif has a slope of -1

33. itsjustme_lol

@whpalmer4 that makes more sense

34. whpalmer4

ccc.gif has a slope of -3/2

35. itsjustme_lol

idk whati was thinking lol. sorry :P

36. whpalmer4

it's late, unless you're in Asia :-)

37. itsjustme_lol

haha. can you help me with one more? thats is all. ill open it in a new question thoughif you are willing to

38. whpalmer4

okay