Answer:
B.
Step-by-step explanation:
A polynomial is an expression consisting of variables and coefficients, that involves only the operations of addition, subtraction, multiplication, and non-negative integer exponents of variables.
[tex]A.\ \dfrac{7}{x^2}=7x^{-2}\qquad\bold{NOT}\\\\B.\ x-\sqrt7\qquad\bold{YES}\\\\C.\ \dfrac{7}{\sqrt{x}}=7x^{-\frac{1}{2}}\qquad\bold{NOT}\\\\D.\ \sqrt{7x}=\sqrt7\cdot\sqrt{x}=\sqrt7 x^\frac{1}{2}\qquad\bold{NOT}[/tex]
