## anonymous 5 years ago A. x = 2 B. x = 2.5 C. x = -1 D. x = 0.5

1. anonymous

So what's the question?

2. anonymous

x^2-3x=-5/4 Which choices are solutions to the following equation?

3. anonymous

Have you tried using the quadratic equation?

4. anonymous

no how ?

5. anonymous

this is the quadratic:$-b \pm \sqrt{b ^{2}-4ac}/2a$

6. anonymous

is it -1

7. anonymous

sorry it didnt come out right http://en.wikipedia.org/wiki/Quadratic_equation

8. anonymous

no its going to be two values

9. anonymous

so you first want to set the given equation =0 kk? How do you do that?

10. anonymous

yea -1 and 2

11. anonymous

do wht .

12. anonymous

$x ^{2}-3x+5/4$

13. anonymous

all that =0

14. anonymous

wht ? confused .

15. anonymous

whts tht equation for .

16. anonymous

kk wait

17. anonymous

okay

18. anonymous

$ax ^{2} + bx + a =0$ where you plug is a b c in the quadratic equation $(-b \pm \sqrt{b ^{2}-4ac})/(2a)$

19. anonymous

to get to values

20. anonymous

21. anonymous

in this case a=1 b=-3 a=5/4

22. anonymous

umm just plug it in I gave you want to plug in

23. anonymous

it didnt give me no answer

24. anonymous

just plug in x =2, x = 2.5, x = -1 and x = 0.5 in the equation and see which value solves it. That will be your answer.

25. anonymous

im still aint geting no answer something wrong

26. anonymous

put x = 2 in $x ^{2}-3x = -5/4$

27. anonymous

you will get $2^{2}-3*2 = -5/4 => 4-6 = -5/4=>-2=-5/4$

28. anonymous

29. anonymous

-2 is obviously not equal to -5/4. so x = 2 is not the answer. similarly put x = 2.5, x = -1, x = 0.5 in the equation and see which one solve the equation

30. anonymous

No, i can't do your problem for you. I can only show you how to do your problem

31. anonymous

well , i dont know how to do this so . its only right if you do .

32. anonymous

I showed you how to do it. just follow the steps.

33. anonymous

rd can you tell me how to put it in the calculator .

34. anonymous

Do you you know how to square things?$X^2$ ?

35. anonymous

yess that = 1/2

36. anonymous

no $x^2 = x \times x$

37. anonymous

1/4

38. anonymous

so just replace x with the given values and if the the equation makes sense then it works.

39. anonymous

Do you know how to multiply and subtract?

40. anonymous

yeaa

41. anonymous

then just replace X with all the given values

42. anonymous

and if the equation makes sense then thats one of the answers

43. anonymous

so you sayinq 1/4 subtract all choices .

44. anonymous

how did you get 1/4

45. anonymous

1/2*1/2

46. anonymous

well i got -1 thts the only answer i got

47. anonymous

48. anonymous

49. anonymous

- 1 and 0.5

50. anonymous

then you must have done some calculation wrong. Post what you got when you substituted x = 0.5

51. anonymous

cant view pics, permission denied.

Your reluctance to substitute the answers from using the quadratic formula is discouraging. The two answers you should of gotten were 5/2, AND 1/2. Substituting the 5/2 into your original formula would of resulted in:$(5/2)^{2}-15/2+5/4=0$ 25/4-15/2+5/4=0 25/4-30/4+5/4=0 0=0 5/2 is a good answer. Now check out the 1/2