## andriod09 3 years ago Multiplying binomial by a trinomial now. Equation in comments

1. andriod09

(4x^3-y^4)(3x+4x^8-9)

2. andriod09

@ganeshie8

3. ganeshie8

same method, we distribute term by term

4. ganeshie8

\((4x^3-y^4)(3x+4x^8-9) \)

5. ganeshie8

\((\color{green}{4x^3}-y^4)(\color{green}{3x+4x^8-9}) \)

6. andriod09

I can't see equation using the buttons.

7. ganeshie8

first distribute 3x^3, then \(-y^4\)

8. ganeshie8

ohh i think there is some bug, its not working properly i heard mods were saying equation editor not working properly

9. andriod09

(4x^3-y^4)(3x+4x^8-9) is the equation.

10. ganeshie8

hmm didnt get u

11. andriod09

you put (3x^3) its (4x^3)

12. ganeshie8

oh gotcha :)

13. ganeshie8

lol that was a typpo.. nothing to do wid editor hehe \( (\color{green}{4x^3}-y^4)(\color{green}{3x+4x^8-9}) \)

14. andriod09

okay.

15. ganeshie8

yea distribute \(4x^3\) first

16. andriod09

okay.

17. andriod09

is it: (12x^3+16x^11y^5-36x^3)?

18. ganeshie8

\((\color{green}{4x^3}-y^4)(\color{green}{3x+4x^8-9}) \) \(\color{green}{4x^3}(\color{green}{3x+4x^8-9}) - y^4(3x+4x^8-9) \)

19. andriod09

I can't see the equations used from the buttons! please just type them! im totally confunsed. :/

20. ganeshie8

oh you cant see the latex thats frustrating

21. andriod09

all i see is \((\color{})(\color{}{}) \) but fulled with the equation

22. ganeshie8

(4x^3 - y^4)(3x+4x^8-9) 4x^3(3x+4x^8-9) - y^4(3x+4x^8-9)

23. andriod09

anyhoo, i have (12x^3+16x^11y^5-36x^3)

24. ganeshie8

is that better

25. andriod09

yea, thank you i can read it now! :)

26. ganeshie8

4x^3(3x+4x^8-9) - y^4(3x+4x^8-9) (12x^4 + 16x^11 - 36x^3) - (3xy^4 + 4x^8y^4 - 9y^4)

27. andriod09

i have to condense my paper, give me a second.

28. ganeshie8

(12x^4 + 16x^11 - 36x^3- 3xy^4 - 4x^8y^4 + 9y^4)

29. ganeshie8

ok if u see any like terms, just add them. i think somthing went wrong in ur answer.. . check :)

30. andriod09

for which part of the equation though?

31. ganeshie8

i dont see any like terms. so thats it i hope

32. ganeshie8

(12x^4 + 16x^11 - 36x^3- 3xy^4 - 4x^8y^4 + 9y^4)

33. andriod09

12x^4 + 16x^11- 36x^3, 3xy^4 - 4x^8y^. are all like terms

34. ganeshie8

why do u think they are like terms

35. andriod09

they are all the same i.e. (x)^4,(x)^11,(-x)^3; (xy)^4,(x)^8(y)^4

36. andriod09

@ganeshie8

37. ganeshie8

(x)^4 and (x)^11 are not like terms

38. ganeshie8

to be called as like terms, terms should satisfy two things- 1) variable letters, for example x, y 2) exponent of variables

39. ganeshie8

terms listed by you are satisfying first condition. but they are failing second condition

40. ganeshie8

if u see, (x)^4,(x)^11 first one has an exponent of 4, and second one has an exponent of 11 so they are not like terms. we cant add them

41. andriod09

oh but they are. they are both (x)s. so by that, all you would do is att the exponets and the numerals.

42. ganeshie8

for addition, BOTH variable(x)s and exponents(4, 11) MUST be equal for multiplication, variables must be equal.

43. ganeshie8

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44. andriod09

@myininaya Hold on ima get a moderator to see whos right. i don't doubt you or anything, i just think that because they are both (x)s, then they could be added.

45. ganeshie8

|dw:1348066394415:dw|

46. ganeshie8

hmm

47. andriod09

How? |dw:1348066447218:dw|

48. ganeshie8

|dw:1348066558698:dw|

49. ganeshie8

50. andriod09

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51. ganeshie8

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52. ganeshie8

exponent must match, then only they are called like-terms, like-terms we can add

53. andriod09

@Callisto @cshalvey @myininaya @amistre64

54. andriod09

I don't get it though, lets see if we can get a mod in here to help me explain it.

55. ganeshie8

ok

56. andriod09

@Callisto @cshalvey @myininaya @amistre64

57. andriod09

@Callisto @cshalvey @myininaya @amistre64

58. andriod09

callisto, can you explain how (x)^4and(x)^11and(-x)^3(stop)(xy)^4And(x)^8(y)^4 arn't like terms? the (stop) seperates two different types of variables

59. andriod09

@ganeshie8

60. Callisto

@ganeshie8 has explained it actually. For like terms, the unknown variable should be the same, and of the same power. For instance, x^4 and x^5 are not like term. Even though they share the same variable, their powers are not the same. So, we cannot do addition or subtraction for these two terms.

61. andriod09

but to be a like term, they have to be the SAME variable though, so wouldn't you add the exponites? x^4+x^5=x^9??

62. Callisto

To be a like terms, there are TWO conditions: 1. same variable 2. same variable of the SAME POWER For x^4 and x^5, they have the same variable x. I think you agree on that. But the problem comes when they fail to meet the SECOND condition, that is they do NOT share the SAME power - for x^4, the power of x is 4; for x^5, the power of x is 5. So, in this case, they CANNOT be added together nor subtraction from each other.

63. Callisto

Perhaps you should know this: x^a + x^b ≠ x^(a+b) BUT! (x^a) (x^b) = x^(a+b) when x is a non-zero real number and a, b are integers.

64. andriod09

Ohh. I MUST FAIL EPICLY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

65. Callisto

It's okay!

66. andriod09

no. i fail epicly. its a fact of life

67. Callisto

It's okay... When you don't fail again!

68. Callisto

So, do you understand it now?

69. andriod09

What about the 12x^3 and the -36^3? arn't they like terms?

70. andriod09

wait, never mind. i fail......... AGAIN

71. Callisto

They are the like terms, aren't they?

72. andriod09

i forgot the the 4x^3*3x=12x^4 not ^3

73. andriod09

Hi hartnn

74. Callisto

Oh.. Just be careful next time :)

75. andriod09

i will

76. hartnn

u won't fail @andriod09 , u are learning from great teachers @ganeshie8 and @Callisto :)

77. andriod09

@hartnn ik its just that i NEVER see the slightest thing, whether in math or irl, it makes me annoyed

78. hartnn

practice and u will become good........

79. andriod09

ik i will. Thanks. |dw:1348068458083:dw|