1) 1+x=t³   t=∛(1+x)     x-gt;0     t-gt;1
     x=t³-1=(t-1)(t²+t+1)
    x/((∛(1+x)-1) =(t-1)(t²+t+1)/(t-1)=t²+t+1
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      =lim   (t²+t+1) =3
         t⇒1
                     ответ 3
2)
t^(15) =x;     x⇒1  t⇒1
x^(1/5) =t³
x^(1/3)=t^5
(1-x^(1/3)) / (1-x^(1/5)) =(1-t^5) / (1-t³) = t² +(1-t²)/(1-t³)=
=t²+ (1-t²)/ ((1-t)² *(t²+t+1)) =t² +1/(t²+t+1)
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        = lim (t²+1/(t²+t+1)=(1+1/3) =1 1/3
           t⇒1
   ответ 1 1/3