Simplify x + 2/ x^2 - 6x - 16 divided by 1/9x

Can somebody me out with this question

Find the gradient of f(x, y,z)equals=left parenthesis x squared plus y squared plus z squared right parenthesis superscript negative 1 divided by 2 baseline plus ln left parenthesis x right parenthesis x2+y2+z2−1/2+ln(xyz) at the point left parenthesis negative 2 comma 1 comma negative 2 right parenthesis(−2,1,−2).

What set does not contain -3 the set of all real numbers the set of all integers the set of all whole numbers the set of all rational numbers