angelwings996 Couple of Math questions, please help! 1. What is the solution of the equation? sqrt(2x - 10) - 5 = x 2. What is the simplest form of the radical expression? 3*cube root(2a) - 6*cube root(2a) 3. Rewrite ^n sqrt(x^m) using a rational expression one year ago one year ago

1. angelwings996

For Number 2$3\sqrt[3]{2a} - 6\sqrt[3]{2a}$

2. angelwings996

For number 3 $\sqrt[n]{x ^{m}}$

3. completeidiot

number 1- move the 5 over to the other side square both sides expand solve for zero on one side factor solve for x

4. completeidiot

number 2- use the distribution property of multiplication but backwards

5. sammi904

Part 1: Solve the following quadratic equation using one of the methods listed below. Part 2: Using complete sentences, explain why you chose the method you used. Equation: 0 = x2 + 6x + 3 Methods: Completing the Square Factoring Quadratic Formula Graphing can someone help?

6. angelwings996

@sammi904 Why do I need to explain the methods I used ?

7. completeidiot

number 3 $\sqrt[n]{x}=x^{\frac{1}{n}}$

8. angelwings996

@completeidiot so far for number 1, I got $2x + 13 = 5x ^{2}$

9. completeidiot

you screwed up somewhere please show me steps

10. angelwings996

Oh I think I get what I did wrong. I times 5 with x instead of adding it so it would be $2x + 10 = (x + 5)^{2}$ Right?

11. syhna

2x-10 = (x+5)^2 2x-10 = x^2 + 10x + 25 0 = x^2 + 8x + 35

12. angelwings996

Okay, but how would you find the solution of the equation? @syhna

13. completeidiot

14. angelwings996

Okay, I'll use the Quadratic Formula so A = 1, B = 10 and C = 25 correct?

15. completeidiot

no, look at syhna's steps

16. angelwings996

Ohh sorry I was looking at the wrong one. A = 1 B = 8 and C = 35

17. completeidiot

yes

18. angelwings996

Okay, I get number 1 now, what about number 2 ?

19. completeidiot

i suggest factoring, for the practice

20. angelwings996

I'm not good at factoring at all, so that's why I am stuck

21. completeidiot

actually, yes use quadratic formula cause i dont think you can factor it

22. angelwings996

How would I figure out what A, B, and C is?

23. syhna

can #2 be subtracted ? i dont honestly get it

24. completeidiot

ax^2+bx+c=0

25. angelwings996

@completeidiot I'm not sure how to identify a, b, and c in the equation $3\sqrt[3]{2a} - 6\sqrt[3]{2a}$

26. completeidiot

oh for number 2 i said use distribution property of multiplication but in reverse

27. completeidiot

essentially the same as factoring

28. angelwings996

That's what I was asking lol. What do yu mean in reverse?

29. completeidiot

a(b+c)= ab+ac in reverse would be pulling something out de+df=d(e+f)

30. angelwings996

Couldn't I cancel out 2a or no

31. syhna

can this be $\sqrt[3]{2a} = 2a ^{3}$ ?

32. angelwings996

It would actually be $2a ^{1/3}$

33. completeidiot

no it would be 1/3 not 3 and you're missing a parenthesis

34. syhna

a i see complete _ what you said a while ago about the reverse factoring then the prob should be equated to 0?

35. angelwings996

For the equation that you gave me @completeidiot de + df = d(e + f), would d be 2a ?

36. syhna

so cube of a times (3 -6) ????

37. angelwings996

@syhna How did you get that? Did you just substitute them into the equation completeidiot gave us?

38. completeidiot

yes syhna

39. syhna

the two terms had cuberoot of a

40. angelwings996

Oh so the answer for #2 is what you got?

41. completeidiot

2a

42. syhna

so it is -3(cube of 2a)? i think its just the same if we subtracted it

43. completeidiot

yes

44. angelwings996

Yeah, that's what I was thinking that if I had subtracted it I would of got what you came up with because at first I subtracted it and came up with that but wasn't sure if it was right

45. angelwings996

Okay, last question, what would I do for #3 ?

46. completeidiot

you're allowed to have improper fractions as exponents

47. angelwings996

Okay, I know you told me it was $\sqrt[n]{x} = x ^{1/n}$ Is this an equation or the answer

48. angelwings996

@completeidiot

49. completeidiot

thats a general rule of thumbs

50. completeidiot

think of it as x^1

51. completeidiot

now replace the 1 with m

52. angelwings996

Okay so it would be $x ^{m/n} ?$

53. completeidiot

yup

54. angelwings996

Okay, could you go over my answer for number 1 really quick ?

55. angelwings996

The Quadratic formua is $x = \frac{ -b \pm \sqrt{b ^{2} - 4ac} }{ 2a }$ right ?

56. completeidiot

yes

57. syhna

yeah i guess

58. angelwings996

Okay so I plugged it in nd got $x = \frac{ -8 \pm \sqrt{-76} }{ 2 }$ after simplifying everything

59. syhna

in no 1 i dont think im right but i used completing the square and got $-4\pm \sqrt{-19}$

60. completeidiot

61. completeidiot

either that or syhna messed up in his calcualtions

62. angelwings996

Wait, so mine was correct ? Or no

63. completeidiot

dunno, didnt actually do any of the problems

64. syhna

-35 =x^2 + 8x -35 + 16 = x^2 + 8x + 16 -19 = sqrt(x+4) sqrt(-19) = x + 4 $-4\pm \sqrt{-19}$ = x this is what i did.. dunno where i messed up

65. angelwings996

I'm not sure either, but thanks for trying to do the work with me! You were alot of help

66. syhna

welcome

67. whpalmer4

$x=-4\pm\sqrt{-19} = -4\pm i \sqrt{19}$ is correct