Use the equations ∂z/∂x=−∂f/∂x ∂f/∂z and ∂z/∂y=−∂f/∂y ∂f/∂z to find ∂z/∂x and ∂z/∂y for 9yz+4xln(y)=z² .

a) 4ln(y)/z−9y , 9z/z−9y
b) 9z/z−9y ,4ln(y)/z−9y
c) 4ln(y)/9y−z , 9z/9y−z
d) 9z/9y−z , 4ln(y)/9y−z