Answer
$y^{60}-20y^{57}+190x^{54}$
Work Step by Step
Calculate the first three terms of $(y^3-1)^{17}$ by using Binomial Theorem or Binomial expansion.
This implies
$(y^3-1)^{20}=\displaystyle \binom{20}{0}(y^3)^{20}(-1)^0+\displaystyle \binom{20}{1}(y^3)^{19}(-1)^1+\displaystyle \binom{20}{2}(y^3)^{18}(-1)^2$
or, $=(1)y^{60}(1)-20y^{57}+190y^{54}(1)$
or, $=y^{60}-20y^{57}+190y^{54}$