What is the expression \(3x^2-\sqrt{7}x+5\)?

Correct answer: Polynomial

This is a polynomial because the powers of the variable \(x\) are \(2\), \(1\), and \(0\), all of which are non-negative integers. Although \(\sqrt{7}\) is irrational, it is a real number and can be a valid coefficient of \(x\). The presence of \(\sqrt{7}\) does not make the expression a non-polynomial. Exam tip: In a polynomial, variable exponents must be \(0,1,2,\ldots\), while coefficients may be any real numbers.