What is the answer to ab plus 4 plus a plus 4b?

Answer 1

There is no answer, because no question has been asked. It's only an expression.

ab + 4 + a + 4b

It can be tidied up a bit:

Collect the 'a' terms:

a(b+1) + 4 + 4b

Collect the '4' terms:

a(b+1) + 4(1+b)

Collect the (b+1) terms:

(a+4) (b+1)

That's a cleaner, more elegant way to write the same expression. But nothing has changed,

no question is asked, and it's not looking for an answer or a solution.