Dhaka Higher Secondary 2011/4
Forum rules
Please don't post problems (by starting a topic) in the "Higher Secondary: Solved" forum. This forum is only for showcasing the problems for the convenience of the users. You can post the problems in the main Divisional Math Olympiad forum. Later we shall move that topic with proper formatting, and post in the resource section.
Please don't post problems (by starting a topic) in the "Higher Secondary: Solved" forum. This forum is only for showcasing the problems for the convenience of the users. You can post the problems in the main Divisional Math Olympiad forum. Later we shall move that topic with proper formatting, and post in the resource section.
\[\begin{align*}
a + b + c + d + e =& 1\\ a - b + c + d + e =& 2 \\ a + b - c + d + e =& 3\\ a + b + c - d + e =& 4\\ a + b + c + d - e =& 5\end{align*} \]
Find $a$ from the above set of equations.
a + b + c + d + e =& 1\\ a - b + c + d + e =& 2 \\ a + b - c + d + e =& 3\\ a + b + c - d + e =& 4\\ a + b + c + d - e =& 5\end{align*} \]
Find $a$ from the above set of equations.
- leonardo shawon
- Posts:169
- Joined:Sat Jan 01, 2011 4:59 pm
- Location:Dhaka
Re: Dhaka Higher Secondary 2011/4
what does form mean... Anyone please explain...
Ibtehaz Shawon
BRAC University.
long way to go .....
BRAC University.
long way to go .....
- leonardo shawon
- Posts:169
- Joined:Sat Jan 01, 2011 4:59 pm
- Location:Dhaka
Re: Dhaka Higher Secondary 2011/4
i found different answers.....
$a+b+c+d+e=1$ its equation 1.
$a-b+c+d+e=2$ from equation 1 $ a+c+d+e=1-b$ so $b=-1/2$
by doing same in each equation, i have got $a=6$ b=-0.5 c=-1 d=-1.5 and e=-2
if im wrong, please give the correct sollution and whats the meaning question. Somebody please make it clear to me. ! ! !
$a+b+c+d+e=1$ its equation 1.
$a-b+c+d+e=2$ from equation 1 $ a+c+d+e=1-b$ so $b=-1/2$
by doing same in each equation, i have got $a=6$ b=-0.5 c=-1 d=-1.5 and e=-2
if im wrong, please give the correct sollution and whats the meaning question. Somebody please make it clear to me. ! ! !
Ibtehaz Shawon
BRAC University.
long way to go .....
BRAC University.
long way to go .....
- Tahmid Hasan
- Posts:665
- Joined:Thu Dec 09, 2010 5:34 pm
- Location:Khulna,Bangladesh.
Re: Dhaka Higher Secondary 2011/4
i also came up with 11
Last edited by Tahmid Hasan on Sun Jan 30, 2011 10:30 pm, edited 1 time in total.
বড় ভালবাসি তোমায়,মা
- leonardo shawon
- Posts:169
- Joined:Sat Jan 01, 2011 4:59 pm
- Location:Dhaka
Re: Dhaka Higher Secondary 2011/4
bro u made a mistake..HandaramTheGreat wrote:\[ a+b+c+d+e=1 \] \[b+c+d+e=1-a \]
if we add all the 5 equations, we'll get
\[ 5a+4(b+c+d+e)=15 \] \[ 5a+4(1-a)=15 \] \[ \therefore a=11 \]
If we add 5 equations, we get
$5a+3(b+c+d+e)=15$
$5a-3a=15-3$
$a=6$
Ibtehaz Shawon
BRAC University.
long way to go .....
BRAC University.
long way to go .....
-
- Posts:135
- Joined:Thu Dec 09, 2010 12:10 pm
Re: Dhaka Higher Secondary 2011/4
sorry...
- leonardo shawon
- Posts:169
- Joined:Sat Jan 01, 2011 4:59 pm
- Location:Dhaka
Re: Dhaka Higher Secondary 2011/4
its okay Bro... dont worry.
Ibtehaz Shawon
BRAC University.
long way to go .....
BRAC University.
long way to go .....
Re: Dhaka Higher Secondary 2011/4
it was a very easy one....hohoho...bt many got perplexed..