Please help this is due tmrw!

For the function, f(x) = -5x 2, find f(-4).

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).

For each sentence below, find the value of x that makes each sentence true. (515) 5 = 25* x= (813)2 = 4* x=