Question

if a=_b (mod n) a^2=_ b^2(mod 2)

that is supposed to be congruent not equals

Answer 1

so far i have that
since n|(a-b) there is a-b=xn also n|(a^2-b^2) so there is a^2-b^2=nt

just not sure how to prove.
should i prove directly by isolating a variable from n|(a-b) and solving in the second n|(a^2-b^2)? it just looks like a mess when i do