- #1
scottstapp
- 40
- 0
Homework Statement
Prove the following
a is congruent to s(mod 9)
Homework Equations
a=drdr-1***d1d0
a=d0+ d110+ d2102+...+dr10r
s= d0+ d1 +...+dr
The Attempt at a Solution
we know that 10-1=9 so we can say that 10 is congruent to 1(mod 9)
so we know that a is congruent to d0+ d110+ d2102+...+dr10r which is congruent to d0+ d1+ d2+...+dr (mod 9).
Is this a step in the right direction? Does anything else need to be shown?