1. The problem statement, all variables and given/known data Question 1. http://people.math.carleton.ca/~mezo/A2math1102-11.pdf 2. Relevant equations r1 = a modn r2 = b modn r = (a+b) modn 3. The attempt at a solution I used the division algorithm So: a = (q1)n + r1 b = (q2)n + r2 (a+b) = (q3)n + r i isolated for r1 and r2 to get more equations r1 = a - (q1)n r2 = b - (q2)n r = (a+b) - (q3)n r1+r2 = (a+b) -n(q1+q2) I then added a and b together to get the following: a+b = r1+r2 + n(q1+q2) After that, i`m completely lost. This is for question 1 by the way. I've been toying around with this question for 15 hours and i still can't do anything with it. I thought i proved it before but then i realized it wasn't a proof. Please help. I'm dying. Also another thing that i'm having trouble with is 3. I don't understand why it's worth 10 marks. All i see is me setting equation 1 and 2 equal to each other. I don't understand what's so special about that.