Question

Решите уравнение log7 (2x — 1) + log7(5) = 2.​

Answer 1

log7 (2x — 1) + log7(5) = 2

log7 (5(2x-1))=2

log7 (10x-5)=2

10x-5=7²

10x=49+5

10x=54

x=5,4