Ain't it Infinite?!
Algebra
Level
4
\(a,b,c,d,e \in \mathbb{R^+}\), and follow \[a+b+c+d+e=40\] and \[ab+ac+ad+ae+bc+bd+be+cd+ce+de=640\] simultaneously. Determine the SUM of ALL possible values of "a".
by
Kristian Vasilev