## anonymous one year ago Use the quadratic formula to solve 2y2 – 3y = 2. A. {½, 2} B. {½, –2} C. {–½, –2} D. {–½, 2}

1. pooja195

Before the subtract the 2 so the the equation is = to 0 $\huge 2y^2-3y-2$

2. pooja195

What are your a b c values?

3. pooja195

Once you have those we can plug it into this equation AKA Quadratic Formula

4. pooja195

$\huge~x=\frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }$

5. anonymous

I barley started to learn this, do you think you can walk me through it, step by step?

6. pooja195

$\huge~ax^2+bx+c$ $\huge~2y^2-3y-2=0$ Anything that is ^2 will be the A just tell the number ignore the y^2 then anything with a plain vairble will just be the b value in this case it is -3 A number alone is the C value which in this case is -2

7. pooja195

Got it so far?

8. anonymous

yes

9. anonymous

@pooja195

10. pooja195

Good now we plug it in

11. KendrickLamar2014

Step 1. Subtract 2 from both sides: $2y^2−3y−2=2−2$ $= 2y^2−3y−2=0$

12. anonymous

okay! @KendrickLamar2014

13. KendrickLamar2014

Step 2. Factor the Left side: $(2y+1)(y−2)=0$

14. pooja195

$\huge~x=\frac{ -(-3)\pm \sqrt{(-3)^2-4(2)(-2)} }{ 2(2) }$

15. KendrickLamar2014

Step 3. Set the factors to equal 0: $2y+1=0~ or ~y−2=0$

16. pooja195

@KendrickLamar2014 it says to use the quadratic formula not factoring

17. KendrickLamar2014

I know, but you can get the same answer.

18. pooja195

They need to use the quadratic formula its the directions.

19. KendrickLamar2014

$= y = -\frac{ 1 }{ 2 }~or~ y = 2$

20. pooja195

Or just give them the answer...... @ninowletonzalez06 are you allowed to use factoring?

21. KendrickLamar2014

Yah, I was just showing her that there are many ways to solve this equation

22. pooja195

Or have u not learned it because the Quadratic formula comes before factoring @KendrickLamar2014

23. pooja195

Well now i bet that the asker is confused .-.

24. anonymous

a liitle, can you explain it in the easiest form!

25. pooja195

do you HAVE to use the quadratic formula?

26. anonymous

by what the question is asking yes!

27. anonymous

are you still there?

28. pooja195

Ok :) All i did here was plug in the values

29. pooja195

LaTex isnt working i cant finish it .-.

30. pooja195

$\huge~x=\frac{ -(-3) \pm \sqrt{(-3)^2-4(2)(-2)} }{ 2(2)}$

31. anonymous

okay!:)

32. pooja195

$\huge~x=\frac{ 3 \pm \sqrt{(-3)^2-4(2)(-2)} }{ 2(2)}$ simplify whats in the square root but DO NOT square root it

33. anonymous

|dw:1433005023557:dw|

34. anonymous

@pooja195

35. pooja195

(-3)^2-4(2)(-2) thats all just miltiply :P

36. pooja195

*multiply

37. anonymous

9-(-16)

38. pooja195

hmmm nope let me help u out :) i plugged it into a calc and got 25 $\huge~x=\frac{ 3 \pm \sqrt{25} }{ 4}$

39. anonymous

oh okay!:)

40. pooja195

Now we turn it into 2 diffrent problems $\huge \frac{ 3+\sqrt{25} }{ 4 }$ and $\huge \frac{ 3-\sqrt{25} }{ 4 }$

41. pooja195

Do you know how to solve?

42. anonymous

3-5/4

43. anonymous

@pooja195

44. pooja195

im kinda confused on the solvng part :/ ive always used a clac to solve @KendrickLamar2014 do you know?

45. anonymous

help!!!

46. pooja195

@ybarrap can you help solve .-. please :)

47. KendrickLamar2014

What?

48. pooja195

$$\color{blue}{\text{Originally Posted by}}$$ @pooja195 Now we turn it into 2 diffrent problems $\huge \frac{ 3+\sqrt{25} }{ 4 }$ and $\huge \frac{ 3-\sqrt{25} }{ 4 }$ $$\color{blue}{\text{End of Quote}}$$ this

49. pooja195

i use a calc to solve that last step i dont know how to explain it

50. KendrickLamar2014

Oh, to explain or to solve it?

51. anonymous

solve it

52. ybarrap

@pooja195 looks like you've got it covered here

53. KendrickLamar2014

I belive you take the square root of 25, then you add/subtract 3, lastly divide by 4

54. KendrickLamar2014

Ye, thats how you solve it ^

55. anonymous

56. KendrickLamar2014

both

57. KendrickLamar2014

Its two equations

58. anonymous

i confused

59. anonymous

im**

60. KendrickLamar2014

$\frac{ 3 + \sqrt25 }{ 4 }$ $\frac{ 3-\sqrt25 }{ 4 }$ Two equations

61. KendrickLamar2014

$\sqrt 25 = 5$ $3+5 = 8$

62. anonymous

okay! i understand now!

63. KendrickLamar2014

$\frac{ 8 }{ 4 } = 2$

64. anonymous

yes

65. KendrickLamar2014

Can you solve the other equation?

66. anonymous

2/4=2

67. KendrickLamar2014

This equation:$\frac{ 3-\sqrt25 }{ 4}$

68. anonymous

so -2?

69. KendrickLamar2014

No, lets go step-by-step. What is the square root of 25?

70. anonymous

5

71. KendrickLamar2014

Yes, now what is 3-5?

72. anonymous

-2

73. KendrickLamar2014

Yes, now what is $\frac{ -2 }{ 4 }$

74. anonymous

-1/2

75. anonymous

76. KendrickLamar2014

Yes

77. KendrickLamar2014

D is Correct