11. Choose all expressions that cannot be simplified using the quotient rule for exponents. Select all that apply.
(3²)(9⁻¹)(2³) / (8⁵)(7⁻²)
(4⁻²)(x⁻¹) / (4⁻¹)(x⁻²)
(6x⁻⁸z²)(6⁵x⁻¹z²)
q⁻⁵r¹¹ / s⁷t⁻¹⁵