a) 4,8axy: (1,6xy); б) (-0,88abc): (1,1b); в) -0,81pqs: (0,009pq); г) 6,5xz: (-1,3z).

a) 4,8axy ∶ (1,6xy) = (4,8 ∶ 1,6) × (x ∶ x) × a × (y ∶ y) = 3 ∙ 1 ∙ a ∙ 1 = 3a

б) (−0,88abc) ∶ (1,1b) = (−0,88 ∶ 1,1) × a × (b ∶ b) × c = −0,8 ∙ a ∙ 1 ∙ c = −0,8ac

в) −0,81pqs ∶ (0,009pq) = (−0,81 ∶ 0,009) × (p ∶ p) × q × s = −90 ∙ 1 ∙ q ∙ s = −90qs

г) 6,5xz ∶ (−1,3z) = (6,5 ∶ (−1,3)) × x × (z ∶ z) = −5 ∙ x ∙ 1 = −5x

Ответ: a) 3a; б) -0,8ac; в) -90qs; г) -5x