Absolute the stability of the one system of straights management

We obtain the necessary and sufficient conditions of absolute the stability system or form dx/dt = f(u(x1x2)), x,f,uR2; и = Ax, A - const matrix type 2x2 under realization of Hurwitz type conditions: ah1(u1) + bh2(u2) 0, det Ah1(u1)h2(u2) > 0, det A = ad - bc, hk(uk) = fk(uk)/uk, ик ≠ 0, k = 1,2.