Please answerrr!!

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).

Landon wrote that 3−2.6=4. which statement about his answer is true?

Micheal is 4 times as old as brandon and is also 27 years older than brandon. how old is micheal