решите уравнение
x^40/42 + x^5/42=12x^-30/42
x^5/42(x^35/42+1)=12x^-30/42
x^35/42+1=12x^-35/42
x^5/6+1=12x^-5/6
x^5/6=t, t>0
t+1=12/t
t^2+t-12=0
t1=-4<0</p>
t2=3
x^5/6=3
x=3^6/5 =3*3^1/5