Question on circumference, photo attached.

If a =6, what is the value of 2a(3b + 5c)?

What value is equivalent to 5 + [5 × (4 + 2)]? a) 35 b) 45 c) 60 d) 110

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).