two different qiestion need it asap please.

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 three. 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 technicue 1 showed in lecture. In each caxe you should end up with an expression that looks something like 3f)+1 or 3(1+2. That way its clear that the result is in fact one morn or two mere than a multiple of three. Upload a pic/pdf or type directly in the text area (your choice). Use a proof by contraposition to prove the following statement for integers m and n " If 3mn is even, then m or n is even." HINT: By DeMorgan's lawy, when you negate an "or" you get an "and. AL SO: To say that a number is not even is eactly the same as saying the nuamber is. odd Upload a pic/pdf or type directly in the textarea