Please help i need help with stats work

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).

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

The total number of dental clinics total for the last 12 months was recorded