How do you solve this literal equation y=5x-6 for x

Show algebraically that f and g are inverse functions f(x)=x^2/-6; g(x)=square root of 2x+12

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).

Which graph represents the parent function of y=(x+2)(x-2)