
Nov 12th, 2001, 02:40 PM
#1
Thread Starter
Dazed Member
Algebra help.
Can any of you check this out for me. i started getting back into math again and i kind of suck at it. This is a question out of one of my text books and they come up with a diffrent answer and i think they are wrong.
2x^3  x^2 + y where x = 3 & y = 2
I come up with:
2(3)^ 3  (3)^2 + 2
2(27)  (9) + 2
(54)  (9) + 2 = 61
they come up with
2(3)^ 3  (3)^2 + 2
2(27)  (9) + 2
54  9 + 2 = 61
but wouldn't (3^2) be (9) not 9?
Thanks

Nov 12th, 2001, 03:35 PM
#2
PowerPoster
hi
A negative number to the power of an even number returns a positive. So, 3^2 = 9, 3^3 = 27 and 3^4=81
2x^3  x^2 + y where x = 3 & y = 2
2(3^3)  (3^2) + 2
2(27)  (9) + 2
54  9 + 2
= 61
Regards
Stuart

Nov 12th, 2001, 03:36 PM
#3
Frenzied Member
Code:
3 + (3) = 0
so as anything * 0 = 0
3 * (3 + 3) = 0 = (3 + 3) * 3
multiplying out
(3 * 3) + ( 3 * 3) = ( 3 * 3) + ( 3 * 3)
and we can subtract ( 3 * 3) from both sides
(3 * 3) = ( 3 * 3)
(3)^2 = 9
If it wasn't for this sentence I wouldn't have a signature at all.

Nov 12th, 2001, 03:56 PM
#4
Thread Starter
Dazed Member
So the book was basically wrong. I didn't know that a negative number to the power of an even number returns a positive. Thanks that will come in handy.

Nov 12th, 2001, 03:57 PM
#5
PowerPoster
Originally posted by Dilenger4
So the book was basically wrong. I didn't know that a negative number to the power of an even number returns a positive. Thanks that will come in handy.
LOL no, the book was basically right.. you were basically wrong

Nov 12th, 2001, 04:19 PM
#6
Lively Member
Beachbum don't state it like a formula that a negative number squared will give you a positive number. Explain him the logic.
Let's do it with 1
(+1) x (+1) = +1
(+1) x (1) = 1
(1) x (+1) = 1
(1) x (1) = +1
So you see that.. if you multiply a negative number 'a' to another number 'b' the resultant product 'c' has the opposite sign of 'b'.
There fore 1 x 1 x 1
can be processed as
1 x 1 = 1 which in turned multiplied by the third number 1
1 x 1 = 1
like this you can see (1)^{2} = 1 x 1 = +1
while (1)^{3} = 1 x 1 x 1 = 1
Marriage  is not a word, but a sentence.

Nov 12th, 2001, 04:22 PM
#7
Thread Starter
Dazed Member
LOL no, the book was basically right.. you were basically wrong
How do you figure? (3)^2 = 9 which i came up with. The book came up with 9.

Nov 12th, 2001, 04:24 PM
#8
PowerPoster
Originally posted by thinktank
Beachbum don't state it like a formula that a negative number squared will give you a positive number. Explain him the logic.
as Jamie would say ... pfffft!!
Dilinger no that isnt true..  3 ^ 2 = 3 x 3 = 9
Look at Thinktank's post for explanation... and then feel free to say Bollox to him as well!!

Nov 12th, 2001, 04:32 PM
#9
Thread Starter
Dazed Member
thinktank yes you are right. So i guess i could think of it this way.
When multiplying numbers with the same sign, multiply the absoulte value of each number. The product will always be positive whether the numbers are bolth positive or bolth negative
The same for numbers with diffrent signs but the result will always be negative.

Nov 12th, 2001, 04:40 PM
#10
Lively Member
Marriage  is not a word, but a sentence.

Nov 12th, 2001, 04:52 PM
#11
PowerPoster
Sorry Dilinger but u are getting ur negatives mixed up
3 ^ 3 = 27
2 x 27 = 54 so lets store that away
3 ^ 2 = 9 (3 x 3)
and finally +2
so the formula is now 54  (9) + 2 = 61
The minus comes from the formula itself ie
2x^3  x^2 + y
and not fromthe result of x^2
Regards
Stuart

Nov 12th, 2001, 04:58 PM
#12
Lively Member
Marriage  is not a word, but a sentence.

Nov 12th, 2001, 05:00 PM
#13
Thread Starter
Dazed Member
yes you are right (54)  (9) + 2 = 61 I guess the surgeon general was right smoking marijuana does burn brain cells.

Nov 12th, 2001, 05:02 PM
#14
PowerPoster
Originally posted by Dilenger4
yes you are right (54)  (9) + 2 = 61 I guess the surgeon general was right smoking marijuana does burn brain cells.
damn u Dilenger!!! arrghhh
54  9 + 2 = 61
54  (9) + 2 = 43

Nov 12th, 2001, 05:08 PM
#15
Thread Starter
Dazed Member
oh yeah right. *~snicker

Nov 13th, 2001, 04:13 AM
#16
Banned
Pffft you bunch of morons. Bollox to yiz!
Christ you're arguing over algebra... its not like art lads. There's a right way, and a wrong way.
*mutter*stuart*mutter*wrong way*mutter*

Nov 13th, 2001, 04:19 AM
#17

Nov 13th, 2001, 04:22 AM
#18
Banned
Originally posted by beachbum
i like just lots of brotherly love
jesus christ ya puff!

Nov 13th, 2001, 01:37 PM
#19
Thread Starter
Dazed Member
I know what i like too. Jelly doughnuts from my local bakery.
yummy

Nov 18th, 2001, 03:26 AM
#20
Conquistador
we don't have jelly donuts in aus...
do you mean jam donuts?

Nov 18th, 2001, 08:36 AM
#21
Hyperactive Member
well here in the UK we call them doughnuts!
There are 10 types of people in the world  those that understand binary, and those that don't.
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