Question

simplify; please tell how to solve​

Answer 1

Answer:

$( {x + y}^{3} ) - ({x - y}^{3} ) \\ = ({x}^{3} + 3 {x}^{2} y + 3x {y}^{2} + {y}^{3} ) - ( {x}^{3} - 3 {x}^{2}y + 3x {y}^{2} - {y}^{3}) \\ = 3 {x}^{2} y + {y}^{3} + 3 {x}^{2} y + {y}^{3} \\ = {y}^{3} + 6 {x}^{2} y$