5(2-3y^2)^2-15y^4=5(2^2- 2*2*6у^2 + 3^2y^4) - 15y^4= 5(4 - 24y^2 + 9y^4) - - 15y^4 = 20 - 120y^2 + 45y^4 - 15y^4 = 20 - 120y^2 +30y^4
-4x(1+2x^3)^2+15x^4 = -4x (1^2 + 2*1*2x^3 + 2^2x^6) + 15x^4 = -4x = 16x^4 - -16x^7 + 15x^4 = -4x - x^4 - 16x^7
4np^3+2p(n-2p^2)^2 = 4np^3 +2p(n^2 - 2*2np^2 + 2^2p^4) = 4np^3 + 2n^2p - -8np^3 + 8p^5 = 2n^2p -4np^3 + 8p^5