# System of Equations/Logic Puzzle Help

• February 20th 2013, 05:41 PM
Espionage
System of Equations/Logic Puzzle Help
Solve for a+b+c+d+e.

a+b=10
b+c=-7
c+d=3
d+e=11
e+a=1
• February 20th 2013, 07:00 PM
Soroban
Re: System of Equations/Logic Puzzle Help
Hello, Espionage!

Quote:

$\text{Solve for }a+b+c+d+e.$

. . $\begin{array}{ccc}a+b&=& 10 \\ b+c&=&\text{-}7 \\ c+d&=&3 \\ d+e&=&11 \\ e+a&=&1\end{array}$

. . $(a + b)+(b+c)+(c+d)+(d+e)+(e+a) \;=\;10 - 7 + 3 + 11 + 1$

. . $2a + 2b + 2c + 2d + 2e \;=\;18$

. . . . . . $a+b+c+d+e \;=\;9$
• February 20th 2013, 07:54 PM
Espionage
Re: System of Equations/Logic Puzzle Help
Quote:

Originally Posted by Soroban
Hello, Espionage!

. . $(a + b)+(b+c)+(c+d)+(d+e)+(e+a) \;=\;10 - 7 + 3 + 11 + 1$
. . $2a + 2b + 2c + 2d + 2e \;=\;18$
. . . . . . $a+b+c+d+e \;=\;9$