(a^3-b^3)^2 (5y^2+4x^2)^2

Question

(a^3-b^3)^2
(5y^2+4x^2)^2

Answer 1

(a^3-b^3)^2 = a^6+b^6-2a^3b^3

(5y^2+4x^2)^2 = 25y^4+16x^4+40y^2x^2

Answer 2

(a^3-b^3)^2=a^6-2a^3b^3+b^6
(5y^2+4x^2)^2=25y^4+40y^2x^2+16x^4