Having a bit of trouble with this one. At the point markedA, I'm not sure I'm going in the right direction. Immediately after that line I haveB, which I'm showing as a possible alternative, but I'm unsure of that approach as well. Can anyone help me work out which, if either, of the two methods is correct?

Many thanks.

Q.is divisible by 4, for

Attempt:Step 1:For ...

, which can be divided by .

Therefore, is true...

Step 2:For ...

Assume , where is an integer...1

Show that is true...

i.e. can be divided by

=> =>

A=> ...from1above => , which can be divided by 4

B

Thus, assuming , we can say is true & true for ... & all