70%-----------3640
100%---------х
х=3640×100/70
Сокращаем 3640 и 70 на 70
х=520×100=52000
(2х+3)^5=((2х+3)^5)=5(2х+3)^4×(2х+3)=5(2х+3)^4×2=10(2х+3)^4