|
| 20 Sep 2012 01:35 PM |
You are given the following system of two equations: x + 2y = 16 3x – 4y = –2
If you could help me with these I would appreciate it a lot because I'm completely lost on solving it. |
|
|
| Report Abuse |
|
|
| |
|
| |
|
| |
|
|
| 20 Sep 2012 01:38 PM |
| Simultaneous equations urk me. |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 01:44 PM |
| Thanks guys but so far no luck at solving it... |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 01:54 PM |
the answer is hats. lots and lots of hats. |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 01:58 PM |
x+2y=16 3x-4y=-2
use elimination method
|
|
|
| Report Abuse |
|
|
| |
|
|
| 20 Sep 2012 02:00 PM |
All I know how to do is x+ 2y = 16 -2y -2y
:( |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 02:00 PM |
| KhanAcademy didn't have anything useful. |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 02:01 PM |
wat
no
there's two variables in that equation
you can't do that
you have the two equations
use elimination method
make one of the variables in one equation equal with another, then subtract
one of the variables should then be gone while all the other values are subtracted |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 02:09 PM |
3x = 4y-2 x=2y+16
Therefore
3*(2y+16) = 4y-2
6y+48 = 4y-2
6y+50=4y
3y+25=2y
Therefore
3y-2y = 25
Therefore
y=25
Then
x = 50+16 = 66
Finally
y=25 x=66
Unless my math failz me, which it probably has :/
|
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 02:10 PM |
erm
thats not right
plug it back in |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 02:11 PM |
| Still completely lost on this... |
|
|
| Report Abuse |
|
|
| |
|
|
| 20 Sep 2012 02:13 PM |
x + 2y = 16 3x – 4y = –2
y=25 x=66
Let's test this
66 + 50 = 116 =/=16
198 - 200 = -2...
Well crud....
Something tells me this is a trap
Are you sure it's not 116?
Not 16? |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 02:13 PM |
| Thank. (This is my main I didn't realize I was on that account when I posted) |
|
|
| Report Abuse |
|
|
|
| 20 Sep 2012 02:14 PM |
| well hmm still confused on the other questions but all this will help.. |
|
|
| Report Abuse |
|
|
| |
|
|
| 20 Sep 2012 02:16 PM |
x + 2y = 16 3x - 4y = -2
in order to make the elimination method work, you have to multiply one variable so its the same value as the the variable in the other equation. it will also affect the rest of the equation
(3)x + (3)2y = (3)16
also, you have to add everything, not subtract. therefore, the second equation has to be a negative.
-1(3x)+(-1)(-4y)=(-2)
simplified:
3x + 6y = 48 -3x + 4y = 2
you add it all up
10y = 50
divide by 10
y = 5
plug in y, find x
x = 6
|
|
|
| Report Abuse |
|
|