Chap 2: Real Numbers - Spot the Common Mistakes (II)

Revision Exercise 2 (p52 of Textbook) No. 7(b)



23 comments:

  1. [-2+(-7)]^3
    =[-9]^3
    =[(-9) x (-9) x(-9)]
    =729

    ReplyDelete
  2. [ -2 + (-7) ]^3
    = (-9)^3
    = -729

    chengngee

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

    ReplyDelete
  4. [-2+(-7)] ^3
    =(-2)-7 ^3
    =(-9) ^3
    = [(-9)x(-9)x(-9)]
    = 81x(-9)
    = -729

    ReplyDelete
  5. [-2+(-7)]^3
    =(-9)^3
    =(-9) x (-9) x (-9)
    =81 x (-9)
    =(-729)

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

    ReplyDelete
  7. (-2+(-7))^3
    =(-2-7)^3
    =(-9)^3
    =(-9) x (-9) x (-9)
    =81 x (-9)
    =(-729)(ans)

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

    ReplyDelete
  9. (-2)+(-7)=-9
    (-9)x(-9)x(-9)=(-729)

    ReplyDelete
  10. Well done :D
    All of you know that we'll operate what's inside the bracket before tackling the power (since the power is attached to the bracket).

    A few areas to note when presenting your solution:

    (a) Instead of writing
    =-9^3
    It should be written as
    =(-9)^3 since it's -9 being multiplied 3 times.
    otherwise, it's like find the cube of positive 9.

    (b) since -729 is the final answer, then we need not include () anymore... else it looks as if it's not the final solution yet.

    On another note (something extra):
    Did you notice Guang Jun managed to insert the power as a superscript =(-9)³
    do you know how to do that?

    ReplyDelete