Given that a+b=c, a+c=d and b=c+d, where d is a positive integer, what is the greatest value of a?

Guest Nov 14, 2018

#1**+1 **

a + b = c ⇒ b = c - a (1)

a + c = d

c + d = b (3)

Equating (1) and (3)

c + d = c - a

d = - a

So

a = -d

CPhill Nov 14, 2018