2 log7 (x-2) = - 2+log7 (x-10)

Решение

2 log₇ (x-2) = - 2 + log₇ (x - 10)

2 log₇ (x-2) = - 2log₇ 7 + log₇ (x - 10)

log₇ (x-2) ² = log₇ 7⁻² + log₇ (x - 10)

log₇ (x-2) ² = log₇ [ (1/49) * (x - 10) ]

(x - 2) ² = (1/49) * (x - 10)

49 * (x² - 4x + 4) = x - 10

49x² - 196x + 196 - x + 10 = 0

49x² - 197x + 206 = 0

D = 30889 - 4*49*206 = 30889 - 40376 = - 9487 < 0 решений нет