ОДЗ: x >= 0
здесь можно и замену сделать: (sgrtx)+1/2 = t
тогда (sgrtx)-1/2 = t - 1
( (Vx-1/2)^2 / (Vx+1/2) )^3= ( 1/4 )^3
4*(Vx-1/2)^2 = (Vx+1/2)
4*(Vx)^2 - 4*Vx + 1 - Vx - 1/2 = 0
4*(Vx)^2 - 5*Vx + 1/2 = 0
8*(Vx)^2 - 10*Vx + 1 = 0
D = 100-4*8 = 68
(Vx) = (10 + V68) / 16 = (10 + 2*V17) / 16 = (5 + V17) / 8
(Vx) = (5 - V17) / 8
x = (5 + V17)^2 / 64 = (25+17 + 10V17) / 64 = (21 + 5V17) / 32
x = (5 - V17)^2 / 64 = (25+17 - 10V17) / 64 = (21 - 5V17) / 32