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?

Answer 1

Given:
a+b=c .... Eq 1
a+c=d .... Eq 2
b=c+d .... Eq 3
{ d ε Z | d > 0 }
Maximum value of a = ?

Sub Eq 3 into Eq 1:
a + (c + d) = c
a = - d .... Eq 4

At this point, ask yourself "what value of d (remembering that d is a positive integer) will yield the largest possible value of a?".

Answer 2

This is not the way
I need a numerical value for a
If I see that then I will say
Have a great day