1. If then
2. Every positive integer is congruent to the sum of its digits (mod 9).
Thanks for the link for the second one! We just had to prove that so I guess I should have been able to figure that one out but I needed a push in the right direction!
For the first one, I'm still unsure. I actually had what you have written on my paper, but I'm still unsure of how the "b" fits into the problem. I have but I need or right? I could divide by x, giving but can I let since that's a fraction?