Use a proof by cases to show that for any integer n,n(n+3)2 is always either one more than a multiple of three or two more than a multiple of thiree for example, if n=5, then n(n+3)2=5(8)2=38 which is two more than a multiple of three. Follow the exact technique 1 showed in lecture. In each case x should end up with an expression that looks something like 3()+1 or 3()+2. That way it's clear that the result is in fact one more or twa more the a multiple of three. Upload a pic/pdf or type directly in the text area (your choice). Choose a submission type Details Use a proof by contraposition to prove the following statement for integers m and n. If m3n is even, then m or n is even." HINT: By DeMorgan's lawy, when you negate an "or" you get an "and'. ALSO: To say that a number is not even is exactly the same as saying the number is odd