## lolly Group Title What is an equation for the line that passes through points (–1, –4) and (1, 4)? Write the equation in slope-intercept form. (2 points) one year ago one year ago

1. surdawi Group Title

y = mx + b m=(y2-y1)/(x2-x1)

2. surdawi Group Title

@lolly wanna try

3. lolly Group Title

no..but i will..:)

4. Swageraid32 Group Title

(1,-4), m = -4 y = mx + b Sub to find b -4 = -4*1 + b b = 0 ------- y = -4x m = -4 means slope = -4. slope-intercept form of equation of a straight line is y = mx + b. m is the slope. b is the y-intercept. your equation starts of with the slope-intercept generic form of y = mx + b replace m with -4 to get y = -4x + b your line goes through the point (x,y) = (1,-4) that means the x-coordinate is 1 and the y coordinate is -4. to find the y-intercept, you replace y with -4 and x with 1 in the equation and solve for b. your equation of y = -4x + b becomes: -4 = (-4 * 1) + b

5. lolly Group Title

can you set up the equation? then ill solve:P

6. surdawi Group Title

@swiftskier96 is that the answer http://www.algebra.com/algebra/homework/Graphs/Graphs.faq.question.233716.html hahaha

7. surdawi Group Title

(x1,y1) = (–1, –4) (x2,y2) = (1, 4)

8. lolly Group Title

soo y=mx=b? isnt that for finding slope?

9. surdawi Group Title

yes but you need to find m 1st $y=\frac{ y2-y1 }{ x2-x1 }$

10. surdawi Group Title

meant m =

11. lolly Group Title

ook ill try it..hold on..:)

12. lolly Group Title

m=-6

13. lolly Group Title

now what?

14. surdawi Group Title

show me how?

15. surdawi Group Title

m is wrong :D

16. lolly Group Title

really?

17. lolly Group Title

m= 1-4/-1--4. m=-3/3 m=-6

18. surdawi Group Title

(x1,y1) = (–1, –4) (x2,y2) = (1, 4) x1 = -1 y1 = -4 x2 = 1 y2 = 4

19. chrispearson813 Group Title

hi lolly :P

20. lolly Group Title

right..thats what i did..,.i think..?

21. lolly Group Title

hi..:)

22. 03225186213 Group Title

(y-y1)/(y2-y1)=(x-x1)/(x2-x1)

23. lolly Group Title

@surdawi how did i do it rong?

24. surdawi Group Title

(4- - 4)/(1- -1)= 8/2=4

25. lolly Group Title

so m is 4?

26. surdawi Group Title

what you did (x2-y2)/(x1-y1)

27. lolly Group Title

well i thought it was -6..but its not..?

28. surdawi Group Title

m = 4 now you choose wither point and solve for b y = 4x + b

29. lolly Group Title

k hold on ill try again..:)

30. surdawi Group Title

$m=\frac{ y2-y1 }{ x2-x1 }=\frac{ 4- -4 }{ 1- -1 }=\frac{ 8 }{ 2 }=$

31. 03225186213 Group Title

for slope slope=(y2-y1)/(x2-x1) it can be directly solve see the formula that i have given already

32. 03225186213 Group Title

(y-y1)/(y2-y1)=(x-x1)/(x2-x1)

33. lolly Group Title

oooh!!! i got the x1and 2s switched up..ok i see..:)

34. surdawi Group Title

|dw:1351797990809:dw|

35. lolly Group Title

the one with less numbers right?

36. surdawi Group Title

there is no zeros for x or y this time so pick one and solve, it doesnt matter which one

37. lolly Group Title

which one would be easier?

38. surdawi Group Title

either, same thing

39. lolly Group Title

k ill do the one with less numbers..:P

40. lolly Group Title

so 4=4x1=b? 4=b..but we already knew that..

41. surdawi Group Title

both of them has same amount of numbers :p 4=4x1=b? ! why is there an equal to b

42. lolly Group Title

43. lolly Group Title

so 4=4+4...

44. lolly Group Title

4=8? that dosent make sense...

45. surdawi Group Title

4=4x1+ b what is x1 = ?

46. lolly Group Title

-1

47. surdawi Group Title

y1 =?

48. lolly Group Title

-1

49. lolly Group Title

000h!!!

50. lolly Group Title

no it dosent..:)

51. lolly Group Title

-4

52. surdawi Group Title

it should be one of the pairs either (1,4) or (-1,-4) -4 = 4*(-1) + b

53. lolly Group Title

-4=4x-1=4?

54. surdawi Group Title

4*-1=?

55. lolly Group Title

-4

56. surdawi Group Title

-4 = -4 + b how can you keep b on one side?

57. lolly Group Title

58. surdawi Group Title

ok show me how?

59. lolly Group Title

-4=-4+b (then the 4 crosses out) +4 +4

60. surdawi Group Title

-4 +4 = -4 + 4 +b 0 = b y = 4x + 0

61. lolly Group Title

where did the other set of -4=4 come from?

62. surdawi Group Title

you have to add 4 to both sides

63. surdawi Group Title

passes through points (–1, –4) and (1, 4)?

64. surdawi Group Title

65. lolly Group Title

10.:)

66. surdawi Group Title

you should know how to add :P

67. lolly Group Title

lol i do know how to add:)

68. lolly Group Title

69. lolly Group Title

lol @surdawi u sleeping?

70. surdawi Group Title

i went to pray |dw:1351801108941:dw|

71. lolly Group Title

lol were u praying that id understand how to do this? lol jk ook umm anyway i thought b=4?

72. surdawi Group Title

lol muslims pray 5 times a day not only sundays :P ok plug in b = 4 to check y = 4*x + 4 (1, 4) 4 = 4*1 + 4 4 = 8? is that right

73. lolly Group Title

4 is not 8...? im so confused!!

74. surdawi Group Title

thats would be the answer if b was 4 correct answer is y = 4x + 0 = 4x plug in and check and where is my medal at??

75. surdawi Group Title

do you want me to give you problem to do?

76. surdawi Group Title

try solving this What is an equation for the line that passes through points (2,5) and (6,7)? Write the equation in slope-intercept form. (you pay \$10 hehe)

77. lolly Group Title

noo i dont want another problem im too stuck with this one..:)

78. surdawi Group Title

tell what you dont understand |dw:1351802673845:dw|

79. lolly Group Title

i dont really understand what you did..like at all... for the one on the right side...

80. surdawi Group Title

ok (-1,-4) now we need to substitute that into y =mx + b y = -4 x = -1 m = 4 y = m* x + b -4 = 4*(-1) + b -4 = -4 + b we now need to add a 4 to both sides -4 = -4 + b +4 +4 -------------- 0 = 0 + b ===> b = 0

81. lolly Group Title

ok so b = 4 and 0?

82. surdawi Group Title

no only 0 how do you get the 4?

83. lolly Group Title

what we did earlier..

84. surdawi Group Title

we never got b = 4 we got m is 4

85. lolly Group Title

oooh!!!

86. surdawi Group Title

i have to go to my Advance Engineering Math :( right now; which doesnt look like anything on here...try to figure it out; if you still have problems feel free to message me the answer is y = 4x

87. lolly Group Title

k thanks 4 ur help:)