what is the answer to - 20+5p-7z

"- 20 + 5p - 7z " is not a question, and it doesn't beg for an answer.

It's an expression that stands for a number.

In order to determine what the number is, you need to know the

values of 'p' and 'z'. And if either of those changes, then the value

of " - 20 + 5p - 7z " immediately changes too. So the whole thing is

a 'moving target'.