Prove divisibility

[Guest]

1. It is given that 3a is divisible by n and (12a+5b) is divisible by n. Prove that 10b is divisible by n.
2. It is given that (3a+7b) is divisible by n and (2a+5b) is divisible by n. Prove that both: a is divisible by n; and b is divisible by n.

[filonina]

I always hated divisibility topics in college, thanks god I finished it.

[reesekPal]

I always hated divisibility topics in college, thanks god I finished it.

Yeah, me too.

[Guest]

Divisibility rules are a set of general rules that are often used to determine whether or not a number is evenly divisible by another number. Divisibility Rules. Example. 2: If the number is even or ends in 0,2,4, 6, or 8, it is divisible by 2. But I really don't know how it can help here. When I have to learn the divisibility of a specific number I simply use Divided by, but it can't help with this question, unfortunately.