X - 8 = y , 2y(x - 4) = xy + 25 после подстановки ширина у=5, длина х=13.
y = 2x + 3/(4x-1)
y' = 2 - 3*4/(4x-1)^2 = 2 - 12/(4x-1)
x1 = 1
logx(x)/logx(0,1x) + logx(x)/logx(0,5x) = 0
logx(0,5x) + logx(0,1x) = 0
logx(0,5x) = logx(1/(0,1x))
0,5x = 1/0,1x
0,05x^2 = 1
x^2 = 20
x2 = 2sqrt{5}
Ответ: 1; 2sqrt{5}.