Can someone me with all of them plz

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).

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Is the point (0, 8) on the x-axis or y-axis? how do you know?