Log1/2(x+y)=-3 log3(x+2y)=1 системы: 2^x-2^y=28 x+y=7

Logxy+2logyx=3x+y=26logxy=1/logyx   1/logyx+2logyx=3   t=logyx   1/t+2t-3=0   t> 0   1+2t^2-3t=0   d=9-8=1   t=3-1/4=1/2   t2=3+1/4=1   logyx=1/2 x=y^1/2=vy   logyx=1   x=yx1=vy   => x+y=26   vy+y=26   y+vy-26=0   d=1+104=105 vd=v105   y=-1+v105/2   x=26-(v105-1)/2x2=y   2y=26   y=13   x=13