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Can't figure out basic math

Posted: Tue Aug 01, 2006 11:27 pm
by Luke
This is kind of embarrassing. I haven't been in school for over 2 years, so I am taking some practice tests on my college's site. They have problems like this:
- 4(- 9)(2)
What is that even asking? What do the parenthesis do? I don't remember this from school. It just says to solve that. so do I add all those together?? what the hell?

Posted: Tue Aug 01, 2006 11:30 pm
by Luke
nevermind... it's multiplication I'm pretty sure. Somebody slap the stupid out of me please!

I guess this means I'm going to have to start all over with algebra... that sucks and it's sad. ( I can't believe I forgot all this crap already!!!)

Posted: Wed Aug 02, 2006 12:28 am
by timvw
The sequence you wrote down is invalid syntax :P could be a shortened version (Or you missed the multiplication sign (.))

Posted: Wed Aug 02, 2006 12:51 am
by Luke
number between the parenthesis is meant to be operated on kind of like a variable 4x == 4(-10)

Posted: Wed Aug 02, 2006 2:42 am
by GM
I'd treat it as multiplication, and give the answer 72

Posted: Wed Aug 02, 2006 2:43 am
by Luke
GM wrote:I'd treat it as multiplication, and give the answer 72
and you would be right :wink:

Posted: Wed Aug 02, 2006 7:13 am
by hydroxide
With algebra 4(3) == 12. Also 4(3) == 3(4). (4)(3) == 12. (2)(3)(4) == 24.

in case you don't remember, the / sign means division. So, (4)(3)/2 == 6.

Re: Can't figure out basic math

Posted: Wed Aug 02, 2006 9:19 am
by RobertGonzalez
The Ninja Space Goat wrote:This is kind of embarrassing. I haven't been in school for over 2 years, so I am taking some practice tests on my college's site. They have problems like this:
- 4(- 9)(2)
What is that even asking? What do the parenthesis do? I don't remember this from school. It just says to solve that. so do I add all those together?? what the hell?
This is the same as -1 * (4 * (-9) * 2) => -1 * (-36 * 2) => -1 * (-72) => 72.

PS In mathematics, the => means 'yields'.

Posted: Wed Aug 02, 2006 4:57 pm
by Ambush Commander
Just wait till you get to the Sigma notation...

Posted: Thu Aug 03, 2006 12:35 am
by timvw
Just wait till you get to multiple variables equations...

Posted: Fri Aug 04, 2006 10:28 am
by tcsoft
I think you should read this like that (since there are spaces between the - operator and you need to parantese negative numbers):
1 - 4 x (1 - 9) x (2)
:?:

Posted: Fri Aug 04, 2006 10:39 am
by infolock
tcsoft wrote:I think you should read this like that (since there are spaces between the - operator and you need to parantese negative numbers):
1 - 4 x (1 - 9) x (2)
:?:
no... actually that should be ( (1 - 5 ( 1 - 10)) x 2

;)

better yet :

Code: Select all

<?php

$a = 1;
$b = 5;
$c = 10;
$d = 2;

$rst = ( ( ($a - $b) * ($a - $c) ) * $d );
echo $rst;
?>
or even

Code: Select all

<?php
$a = 1;
$rst = ( ( ( $a - ($a + 4) ) * ($a - ($a - 10) ) * ($a + 1) );
echo $rst;
?>
:-D