(2х–5)^2 (2х–5)^8 (2х–5)^10
(--------------)^7 • ------------ : -------------- =
(3х+1)^2 (3х+1)^8 (3х+1)^10
(2х–5)^14•(2х–5)^8•(3х+1)^10
= ------------------------------------------ =
(3х+1)^14•(3х+1)^8•(2х–5)^10
(2х–5)^12
= --------------
(3х+1)^12