I am not good a maths at all please help me please.

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).

Are the corresponding angles congruent? explain why or why not.

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18