Please help to solve "Show that if m is irrational, then 2m+3 is irrational"
Hint: Your proof might look like this:
"Assume that 2m+3 is rational.
Then... (something you can write down immediately).
And so ... (do some algebra).
Therefore ...(something about m), which contradicts the assumption that m is irrational.
Thus the initial assumption produced a contradiction, and so must have been false.
Therefore 2m+3 is irrational."