That conclusion is definitely wrong. Your equation expanded equals: b = (a+b) – (a-b) = a+b – a + b = 2*b For your example a=20, b=10b = (20+10) – (20-10) = (30) – (10) = 20b = 20 + 10 – 20 + 10 = 20 A counter example to disprove this: a=75, b=88 b = […]