math:/

by TrgT • 25 Mar 2008, 16:45 • Journals
I heard you guys are very good at math and I have a test tomorrow so can anyone explain my how to solve this:

{X * Y = 6
{2X+3Y = 13

Both X & Y are the same.

[16:51] <krts-infect> ask me if you need help in maths
[16:51] <krts-infect> i am quite good @ it
[16:52] <krts-TrgT> you know ho to use discriminant ?
[16:56] <krts-infect> nop
Comments
58
▼
flame 25 Mar 2008, 16:48
so x=y?

that means:
2*x+3*x=13
x*(2+3)=13
5*x=13
x=13/5=2,6 ;)

edit: seems i got something wrong
dunno then :(

{X . (<---)Y = 6

what means that dot?
▼
pala 25 Mar 2008, 16:54
and you did 2x+3x = 13
the bold needs to be Y
Parent
▼
foonr 25 Mar 2008, 16:48
X = 5
Y = 1
▼
fing 25 Mar 2008, 16:49
Both X & Y are the same. :c
Parent
▼
perforator 25 Mar 2008, 16:50
No, he means X and Y are the same in both fucntions.. X != Y
Parent
▼
flame 25 Mar 2008, 17:00
seriously how?

1st equation to x

x=6/y

x in 2nd equation

12/y+3y=13

=> two y --> two solutions for y (????)

enlight me
Parent
▼
smokey151 25 Mar 2008, 17:32
everything * Y, then you have a function with two solutions no?
Parent
▼
dEzIrE 25 Mar 2008, 16:49
lol'd @ infect xD
▼
RazZaH 25 Mar 2008, 16:56
x=2 y= 3

lol
▼
perforator 25 Mar 2008, 16:58
{X . Y = 6
{2X+3Y = 13

means

x + 1.5y = 6.5
x = 6.5 - 1.5y

fill in in function 1:

(6.5 - 1.5y) y = 6
6.5y - 1.5y^2 = 6
-1.5y^2 + 6.5y - 6 = 0

abc formula -> y can be either 1.33 or 3

-----

Fill in the values

X . 1.33 = 6
X = 4.5

2(4.5) + 3(1.33) = 13

X . 3 = 6
X = 2

2(2) + 3(3) = 13

------

Answers:
1) X = 4.5 and Y = 1.33
2) X = 2 and Y = 3
▼
RazZaH 25 Mar 2008, 16:59
lol ur rly bored right ? xD

i did that in 10 sec


edit:

but k .. u have 2 answers ;)
Parent
▼
perforator 25 Mar 2008, 17:02
You have to make sure you find every answer ;p
Parent
▼
RazZaH 25 Mar 2008, 17:02
ye..my teacher tells me that every day xD
Parent
▼
TrgT 25 Mar 2008, 17:04
Dat heb je goed, maar waar haal je die 1.5 vandaan?
Parent
▼
perforator 25 Mar 2008, 17:05
2x + 3y = 13

alles door 2 delen
Parent
▼
TrgT 25 Mar 2008, 17:09
ok tot zover snap ik het,

maar

(6.5 - 1.5y) y = 6
6.5y - 1.5y^2 = 6

waarom moet je dat tot de macht doen?
Parent
▼
perforator 25 Mar 2008, 17:19
omdat als het tussen haakjes staat, je de Y met beide getallen tussen haakjes moet vermenigvuldigen
Parent
▼
flame 25 Mar 2008, 17:02
CAS is nice
but as you might notices your math fellow isnt allowed to use one otherwise he would have harder tasks

besides your solution is wrong
Parent
▼
RazZaH 25 Mar 2008, 17:05
sure is my solution right....

2,3 is right rofl...

i just didnt write up the 2nd solution cuz i would need more time for that omg
Parent
▼
flame 25 Mar 2008, 17:09
nope its not right because you havent wrote the second solution for x and y But you are willing to help and thats nice ;)
Parent
▼
hex4 25 Mar 2008, 17:21
how can you use 1.33 if it's a recuring number?

it's not accurate...
Parent
▼
perforator 25 Mar 2008, 17:26
I assume 1.33 = 1 + (1/3).. but to be exact you are right, it's easier to write 1.33 than 1 + (1/3). That's why

(0.9999999... = 1 anyways)
Parent
▼
infect 25 Mar 2008, 17:45
havent heard of 4/3 :) ?
Parent
▼
perforator 25 Mar 2008, 17:48
true, too tired
Parent
▼
flame 25 Mar 2008, 17:46
4/3 ? :p

edit fu @ the guy above :(
Parent
▼
smokey151 25 Mar 2008, 17:41
i got the same, seems a lot of others are suckage at maths :)
Parent
▼
pala 25 Mar 2008, 16:59
Y = 1
X = 5 cuz:

X*Y = 6 / *(-2)
2x+3Y=13

-2x*(-2Y)=-12
+
2x+3Y=13
=
Y=1
now put the Y in one of the other functions to get the x
like:
Y=1
2x+3*1=13/ -3
2x=10/ :2
x=5
▼
perforator 25 Mar 2008, 17:00
2x6 + 3x1 = 15?
Parent
▼
pala 25 Mar 2008, 17:05
thx did wrong function @ finding X :P
seems wrong anyway tought
Parent
▼
huumeantti 25 Mar 2008, 17:09
didnt know 5 * 1 = 6
Parent
▼
pala 25 Mar 2008, 17:10
i wish it would be 5+1 so much ;[
Parent
▼
peoples 25 Mar 2008, 17:01
What grade? This seems rather simpletask, and the correct ways to solve it has been given :)
▼
TrgT 25 Mar 2008, 17:11
Works diffrent here then in finland, but it's meant to be for MBO-4 TS6A
Parent
▼
hex4 25 Mar 2008, 17:02
y=3
x=2

2*3 = 6
2x + 3y = 13 i.e 2(2) + 3(3) = 13; 4 + 9 =13

np4me
▼
flame 25 Mar 2008, 17:06
nope
Parent
▼
hex4 25 Mar 2008, 17:07
y not?
Parent
▼
flame 25 Mar 2008, 17:09
there are more solutions possible
Parent
▼
hex4 25 Mar 2008, 17:14
enlight me

the only possible solutions for x*y = 6 are 3*2, 2*3, 6*1 and 1*6, try these numbers in the 2nd equation and you won't get the right answer...
Parent
▼
flame 25 Mar 2008, 17:15
look at perfos post

two x or y in one equation means two solutions
Parent
▼
Vanhaomena 25 Mar 2008, 17:47
Not necessarily.

X * X + Y * Y = 0

How many different solutions?
Parent
▼
morfine 25 Mar 2008, 17:04
{ x = 6 / y (y = 6/x)

liniair combineren en voila...
▼
b 25 Mar 2008, 17:06
what grade?
▼
JOEL 25 Mar 2008, 17:12
X=Y

2X+3Y = 13

-> 5X = 13 , 5Y = 13
-> X = Y = 13/5

dunno about upper shit, im not nerd
▼
smokey151 25 Mar 2008, 17:38
there wouldnt be alot bridges standing if it wasnt for those nerds
Parent
▼
smokey151 25 Mar 2008, 17:38
i have gots two solutions:

1)
y = 3
x = 2

2)
y = 8/6
x = 9/2
pmme if you need info's
▼
TrgT 25 Mar 2008, 18:10
Als in die info zou mogen zou ik dat erg fijn vinden, je antwoorden zijn goed heb je D=b²-4ac gebruikt zoniet heb ik er niks aan aangezien we de discriminant moeten gebruiken.
Parent
▼
smokey151 25 Mar 2008, 19:25
ja kheb het gedaan, pm, sec
edit, nvm, het staat hieronder al
Parent
▼
dinev 25 Mar 2008, 17:41
i lold at quote :D
▼
jurBo 25 Mar 2008, 17:55
lol, challenging ...
▼
TrgT 25 Mar 2008, 18:13
take your time, it took me 2 hours to finnaly understand something :/
Parent
▼
banaan 25 Mar 2008, 19:59
ffs my brains hurt
Back to top