Question

решите уравнение log7 (20x+15)-log7 5=log7 17

Answer 1

ОДЗ
20x + 15 > 0
20x > - 15
x > - 0,75

log 7 ((20x + 15) / 5) = log 7 (17)
(20x + 15)/5 = 17
20x + 15 = 17*5
4x + 3 = 17
4x = 14
x = 3,5

Ответ
3,5