teller one year ago A line passes through the point −6, 1 and has a slope of 4 over 3. Write an equation in slope-intercept form for this line.

1. anonymous

does "4 over 3" mean $$\frac{4}{3}$$?

2. teller

Yes..

3. anonymous

ok use $y-y_1=m(x-x_1)$ with $x_1=-6,y_1=1,m=\frac{4}{3}$

4. teller

Confused... But I will try it 6-1^1= 4/3(x-x^1) ??

5. misty1212

HI!!

6. misty1212

i see you are a bit confused

7. misty1212

you do know that the answer you are supposed to get has an $$x$$ and a $$y$$ in it right?

8. teller

Yes I'm confused and no .That's why I'm asking for help .

9. misty1212

it should look like $$y=mx+b$$ for some $$m$$ and $$b$$

10. misty1212

the $$x$$ and $$y$$ are variables in this expression $y-y_1=m(x-x_1)$ they are the $$x$$ and $$y$$ in the answer the $$m$$ and $$x_1,y_1$$ are numbers @satellite73 showed you what those numbers are

11. teller

So y-1=4/3(x-(-6)

12. misty1212

that looks good

13. misty1212

$y-1=\frac{4}{3}(x+6)$ looks even better since $$-(-6)=+6$$

14. misty1212

you are not done yet though, you still have to solve for $$y$$ which takes exactly two steps

15. teller

So how do I do that?

16. misty1212

a) distribute the $$\frac{4}{3}$$ on the right b) add $$1$$ to both sides

17. misty1212

does that make any sense to you?

18. teller

y=4/3x+9??

19. misty1212

yes!

20. misty1212

$\color\magenta\heartsuit$

21. teller

Mind if you help me with another one?

22. misty1212

sure and say hi to penn for me

23. teller

Hello penn?.?.Don't know who that is lol but Hi... A line passes through the point -2, -4 and has a slope of −7 . Write an equation in slope-intercept form for this line.

24. anonymous

this one is even easier because there is no fraction

25. anonymous

same as before $y+4=-7(x+2)$

26. misty1212

what @satellite73 said, then you have to solve for $$y$$ using the same two steps a) distribute on the right b) subtract 4 from both sides

27. teller

y=-7x-18??

28. misty1212
29. misty1212

yeah looks good

30. teller

A line passes through the point 7, 5 and has a slope of 2 . Write an equation in slope-intercept form for this line. Would it look like this ? y+5=2(x+7)

31. misty1212

not quite

32. misty1212

the reason they were plus before was because each number was negative but the formula is $y-y_1=m(x-x_1)$

33. misty1212

so change those plus signs to minus signs

34. teller

so each time it's a plus it will be a minus and when ever it's a minus it will be a plus?

35. misty1212

yes

36. teller

so y-5=2(x+7) or is y-5=2(x-7)

37. misty1212

second one

38. teller

so y=2x-9?

39. misty1212

looks good

40. teller

A line passes through the point −8, 7 and has a slope of 5/4 . Write an equation in slope-intercept form for this line. y+7=5/4(x+8)

41. misty1212

not quite there is one mistake in a sign do you see it?

42. teller

would it be (x-8)??

43. misty1212

no that part is right

44. teller

so -7??

45. misty1212

yes

46. teller

so y-7=5/4(x+8)

47. misty1212

at the risk of repeating myself, it is $\huge y-y_1=m(x-x_1)$ the minus signs are in the formula

48. misty1212

yeah that is right

49. teller

y=5/4x+17??

50. misty1212

yup

51. teller

it said it was incorrect...

52. teller

it was minus 17..

53. misty1212

no it isn't

54. teller

That's what the problem said and when i hit explain it gave me the answer...

55. misty1212

$y-7=\frac{5}{4}(x+8)\\ y=7=\frac{5}{4}x+10\\ y=\frac{5}{4}x+17$

56. teller

sometimes i think the thing is rigged ...

57. misty1212

was the point$$(7,-8)$$?

58. teller

no -8,7

59. misty1212

yeah sorry that is what i meant

60. misty1212

if the point is $$(-8,7)$$ then it should be $$y=\frac{5}{4}x+17$$

61. misty1212

tell them it is a mistake

62. teller

A line passes through the point −6, -1and has a slope of −5/2 . Write an equation in slope-intercept form for this line. Would it be y+1=-5/2(x+6)

63. misty1212

yes

64. teller

so it would be y=-5/2x-16??

65. misty1212

hmm lets check

66. misty1212

$y+1=-\frac{5}{2}(x+6)$$y+1=-\frac{5}{2}x-15$$y=-\frac{5}{2}x-16$

67. teller

A line passes through the point 6, 1 and has a slope of 2. Write an equation in slope-intercept form for this line. so y-1=2(x-6)?? y=2x-11??

68. misty1212

yes

69. teller

One more problem then I will be done with that subject.I greatly appreciate you for helping me ! A line passes through the point 4, -9 and has a slope of −4 .Write an equation in slope-intercept form for this line. y+9=-4(x-4) or is it y+9=-4(x+4)

70. misty1212

fist one

71. misty1212

first

72. teller

so the final answer would be y=-4x+7

73. misty1212

yes

74. misty1212

you done with them all?

75. teller

said I was incorrect...

76. misty1212

ok lets check

77. misty1212

A line passes through the point (4, -9) and has a slope of −4 right?

78. misty1212

$y+9=-4(x-4)\\ y+9=-4x+16\\ y=-4x+7$

79. misty1212

it is right, if that was the question

80. teller

We are given that the line passes through the point −4, 9 . So, the equation must be true when =x4 and =y−9 . =−9+−44b We can solve this equation for the y -intercept b . −9 =+−44b −9 =+−16b 7 =b We now write the equation of the line in slope-intercept form. =y+−4x7 Here is the answer. =y+−4x7

81. teller

that's what it said

82. teller

but thank you for the help..

83. misty1212

i have read that twice now and it does not make any sense to me

84. misty1212

what does =y+−4x7 even mean?