(а^2- аb)/(a^2-b^2) = [a(a-b)] / [ (a-b) (a+b) ] = a / (a+b)
Ответ: a/(a+b)
Решение
<span>5^(2х+1) - 26*(5^х) + 5 = 0
5^x = t
5t</span>² - 26t + 5 = 0
D = 676 - 4*5*5 = 576
t₁ = (26 - 24)/10 = 1/5
t₂ = <span>(26 + 24)/10 = 5
1) 5^x = 1/5
5^x = 5</span>⁻¹
x₁ = - 1
2) 5^x = 5
x₂ = 1
Ответ: x₁ = - 1; <span>x₂ = 1</span>