Ответы и объяснения

2014-02-02T14:55:12+00:00
Log₀.₅0.05 =  \frac{ log_{2}0.05 }{ log_{2}0.5 } =  \frac{ log_{2} \frac{1}{20}  }{ log_{2} \frac{1}{2}  }=-  log_{2} \frac{1}{20}= log_{2}20
log₂(5-x) + log₂ (4-x) = log₂20
ОДЗ: 5-x>0
         4-x>0
log₂ ((5-x)(4-x)) = log₂20
(5-x)(4-x) = 20
20 - 5x - 4x + x² = 20
x² - 9x = 0
x (x-9) = 0
x₁ = 0
x₂ = 9 не удов. ОДЗ
Ответ: 0