## anonymous one year ago f(x) = 2.5x – 10.5 in this equation, i subtract 2.5 from 10.5, correct? medal and fan! :)

1. triciaal

where is the rest of the question?

2. anonymous

well, it's part of a graph.

3. triciaal

all you have is the equation. It does not say what to do.

4. anonymous

i just need to know if i am to subtract 2.5 from 10.

5. anonymous

i have to complete a table to solve the equation 2.5x - 10.5 = 64(0.5^x)

6. triciaal

y = f(x) slope = 2.5 and b = -10.5 y = mx + b

7. anonymous

I don't know if that helps me.

8. anonymous

need to see the table? so you can see the full problem?

9. triciaal

from the table what value of x will make the equation true?

10. anonymous

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11. anonymous

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12. triciaal

for example when x = 0 on the left f(x) = -10.5 and on the right 64(0.5^x) = 8 -10.5 is not equal to 8 so x = 0 is not a solution

13. triciaal

** on the right = 64 -10.5 not = 64 so x = 0 not a solution

14. triciaal

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15. triciaal

replace x with the number and compute

16. anonymous

they gave me that graph, i can't change the 2. i probably should change the 10 .

17. triciaal

but do you see how I did x = 0 before I saw the table

18. triciaal

they want you to do from x = 2 to x = 6

19. triciaal

since you have the graph maybe you just have to look at the graph and fill in the table

20. triciaal

the solution is where the graphs intersect

21. anonymous

okay, but that's not what i'm asking. i'm asking if i am to subtract 2.5 from 10.5 to solve the f(x) equation.

22. anonymous

thank you for explaining the other stuff though. :)

23. triciaal

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24. triciaal

you have to use the value of x then you can compute. you cannot subtract a number from a variable. you can only add or subtract when you have like terms

25. triciaal

a term with x is not like a number apples and oranges

26. triciaal

to directly answer your question no you cannot subtract 10.5 from 2.5 x because they are not like terms.

27. anonymous

i understand. so do i subtract how do i find the first input on the table?

28. anonymous

i didn't mean to send the "so do i subtract" part. sorry.

29. triciaal

I did when x = 0 I did when x = 3 and I did when x = 6 follow along replace the x with 4 and compute fill in the table replace the x with 5 and compute then fill in the table

30. triciaal

again, the solution is the value of x that gives the same value in the table for f(x) and for g(x)

31. triciaal

you said you have the graph. the solution is the point where the lines cross/intersect

32. anonymous

oh, i didn't mean graph earlier, i meant table. the graph comes in later, to check the work.

33. anonymous

and i'm sorry, but i don't know if i'm following you. so the x in 2.5x - 10.5 is either 2, 3, 4, 5, or 6? and i fill the x in the f(x) and g(x) equations with those numbers until they equal each other?

34. anonymous

for example: f(x) = 2.5(2) - 10.5 = 5 - 10.5

35. triciaal

basically yes look again at the drawing see how I did x = 3

36. anonymous

and: g(x) = 64 (0.5^2) = 64 (.25)

37. triciaal

the graphs intersect when x = 5

38. anonymous

so the answer is x = 5?

39. triciaal

you need to fill in the table

40. triciaal

you need to fill in the table

41. anonymous

f(x) = 2.5x - 10.5 = 2.5(2) - 10.5 = 5 - 10.5 = -5.5 correct so far?

42. triciaal

yes

43. anonymous

okay. then: g(x) = 64(0.5^x) = 64(0.5^2) = 64(.25) = 16 correct?

44. anonymous

and for f(x) 2 i would fill in -5.5, and for g(x) 2 i would fill in 16?

45. triciaal

I can't send the graph as an attachment. when you are finished with the table will send you the link

46. anonymous

okay so you want me to fill it in on here? i can draw it on here.

47. triciaal

basically yes the correct notation is f(2) and g(2)

48. anonymous

okay

49. triciaal

click on the drawing above and do when x = 4 and x = 5

50. anonymous

okay

51. anonymous

0.5^3 would be .125 or 1.25?

52. anonymous

oh it would be 1.25.

53. triciaal

no

54. anonymous

.125?

55. triciaal

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56. triciaal
57. triciaal

so you can input and see the graph

58. anonymous

oh i understand. so .125.

59. triciaal

I have to go. I sent the link for the calculator you might want to see the graphs. Intersection is at (5,2) Please review your basic stuff so you can focus on the new material. Always post all of the question so you can get the right help fast. All the best with your studies.

60. anonymous

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61. triciaal

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62. anonymous

i know i got it right, so thank you so much for all your help and for dedicating this much of your time to assisting me. i really understand what i'm doing and i enjoy it as well, just like i used to. i really appreciate everything tonight. :)

63. triciaal

you are welcome