(i) `(28x^4)/(56x) = (28**x**x3)/(2**28**x) = x^3/2`
(ii)`(-36y^3)/(9y^2) = (-4**9**y^2**y)/(9**y^2) = -4y`
(iii)`(66pq^2r^3)/(11qr^2) = (6**11**p**q**q**r**r^2)/(11**q**r^2) = 6pqr`
(iv)`(34x^3y^3z^3)/(51xy^2z^3) = (2**17**x**x^2**y**y^2**z^3)/(3**17**x**y^2**z^3)=(2x^2y)/3`
(v)`(12a^8b^8)/(-6a^6b^4) = (2**6**a^6**a^2**b^4**b^4)/(-6**a^6**b^4) =-2a^2b^4`