Question

5th's 2nd question
plz urgent!!!

Answer 1

$(a - b)( {a}^{2} + {b}^{2} + ab) - (a + b)( {a}^{2} + {b}^{2} - ab) \\ {a}^{3} - {b}^{3} - ( {a}^{3} + {b}^{3} ) \\ - 2 {b}^{3}$
please follow me

Answer 2

answer is in attachment