Monday, 17 February 2014

Algebra... Which is larger? (II)


Jennifer says, "5x2  is always smaller than  (-5x)2. "

Do you agree? Explain your answer. 

Enter your response in Comments.

This question is compulsory.

23 comments:

  1. This comment has been removed by the author.

    ReplyDelete
  2. I do not agree with Jennifer as:
    Let x be 1/0
    5x^2=5X1/0^2
    =infinity
    (-5x)^2=(-25)X1/0^2
    =infinity

    ReplyDelete
  3. No. If x=1 then 5x squared is 5 and (-5x)squared is 25 so in this case 5x squared is smaller than (-5x) squared. However for numbers larger or smaller than one 5x squared is the same as (-5x) squared e.g. x=2 5x squared = 100
    (-5x) squared is still 100.

    ReplyDelete
  4. no. It is wrong.
    Let x be 1.
    Then, 1x1=1
    5x1=5
    While -5x1=-5
    -5 square= 25
    Therefore, (-5x) square is always bigger than 5x square.

    ReplyDelete
  5. No. If X=1 then 5Xsquare will be 25.
    Thus, (-5X)square will also be 25, which means they are equal, so Jennifer is wrong

    ReplyDelete
  6. This comment has been removed by the author.

    ReplyDelete
  7. She is right unless x=0
    This is because
    Expression 1: 5xsq
    Expression 2:(-5x)square(sq)=(-5)sqx(x)sq=25xsq
    Compare Ex 1 and 2, Ex 1 is smaller.

    ReplyDelete
  8. No.
    If X were 5, 5x square would equal to 25x. (-5x) square would also equal 25x therefore Jennifer is wrong.

    ReplyDelete
  9. She is wrong (unless there is a third option again XD)
    If X is 1 then 5xsq will be 25 while (-5x)sq is also 25 which means they are the same,thus Jennifer is wrong.

    ReplyDelete
  10. She is wrong. (I hope this isn't a 'third option' kind of thing.)
    If x were to be 5, 5xsq would be 25 while (-5x)sq would also be 25, which shows that the answers are indeed the same. Therefore, Jennifer is wrong

    ReplyDelete
  11. No.
    If x = 1, 5x^2=25
    (-5x)^2 = -25
    So, 5x^2 is not always smaller than (-5x)^2

    ReplyDelete
  12. yes.
    if x = 1
    5 x 1^2 = 20
    -5^2 x 1^2= 27

    ReplyDelete
  13. No,they are equal,
    X=10
    (5x10)sq=2500
    -(5x10)sq=2500

    ReplyDelete
  14. No. If x = 1 then both of the results would be the same, but if x is more than one, then 5x^2 would be smaller. But nonetheless, it shows that 5x^2 is not always smaller than (-5x)^2.

    ReplyDelete
  15. YES..

    x is a variable --- it can change.

    If 'x' is zero, both answers are zero and they are the same.

    If 'x' is 5, 5x to the power of 2 means (5X5) X (5X5) = 625
    and (-5x) to the power of 2 means (-5 X 5 ) X (-5 X 5) = 625!
    So both of them are the same.
    Even If 'x' is 1, 5x to the power of 2 means (5 X 1) X (5 X 1) = 25
    and (-5x) to the power of 2 means (-5 X 1) X (-5 X 1) = 25
    So, both of them will be the same , No matter what, even if x is zero.

    ReplyDelete
  16. No.
    If x is 1, then, 1 x 1 = 1

    5 x 1 = 5
    -5 x 1= -5
    -5 square = 25
    So, (-5x) squared is always bigger than 5x squared.

    ReplyDelete
  17. I do not agree.
    Let's take x as 10.
    5x10=50
    50x50=250

    And...

    -5x10=(-50)
    -50x-50=(-100)

    So,here you can see that 5x to the power of 2 is greater.

    ReplyDelete
  18. I don't agree
    Take x as 20
    5x20=100
    100x100=10000

    -100x-100=10000
    So they are equal.

    ReplyDelete
  19. I do not agree, because if x = 10, then (5 x 10)^2 = 2500 and ( -5 x 10)^2 = 2500, and so they are equal.

    ReplyDelete
  20. This comment has been removed by the author.

    ReplyDelete
  21. This comment has been removed by the author.

    ReplyDelete
  22. I do not agree.

    Scenario 1

    If x = 1 ,

    5x^2 = 5 x 1 x 1 = 5
    (-5 x x)^2 = (-5 x 1 ) x (-5 x 1 ) = 25
    5x^2 is smaller.

    Scenario 2

    If x = 0 ,
    5x^2 = 5 x 0 x 0 = 0
    (-5 x x )^2 = (-5 x 0 ) x (-5 x 0 ) = 0
    Both of their values are 0 thus none of them is smaller.

    From the two scenarios above , we can conclude that Jennifer is wrong.

    ReplyDelete