If 4 divides a^2-3b^2, then at least one of the integers a and b is even.

Step-by-step explanation:

The proof can be done by contradiction. Suppose both a, and b weren't even. So that a, and b are both odd. This means they both look like

(for some integers k and l)

So, let's compute what would be in this case:

which notice wouldn't be divisible by 4. This shows then that since is divisible by 4, at least one of the integers a and b is even.

well there are two answers for that.

1: you need 120 ones then that will equal up to 120.

2: you could also do one 100 and 2 tens.

those are the answers that i have thought of.

entering that problem on the tube might get you an answer