To determine the constant term in an algebraic expression, we need to look for the term that does not contain any variables. The given algebraic expression is:
[tex]\[
-2x^2 + 17 - 15x + 7xy
\][/tex]
Now, let's identify each part of the expression:
1. \(-2x^2\): This term contains the variable \(x\).
2. \(17\): This term does not contain any variables.
3. \(-15x\): This term contains the variable \(x\).
4. \(7xy\): This term contains the variables \(x\) and \(y\).
Among these terms, the only one that does not include any variables is \(17\). Therefore, the constant term of the expression is:
[tex]\[
\boxed{17}
\][/tex]
