Решить систему урaнений 2x-y=1, 3^y/27=(1/9)^(x-2)

2x-y=1 <=> y=2x-1

3^y/27=(1/9)^(x-2) <=>
3^(2x-1)/27=(1/9)^(x-2) <=>
3^(2x-1)/3^3 =(3^(-2))^(x-2) <=>
3^(2x-1-3) = 3^(-2(x-2)) <=>
2x-4 = -2x +4 <=>
4x=8 <=>
x=2

y=2*2-1=3

Проверка: 3^3/27 = (1/9)^(2-2) =1