Respuesta :

Hrishii

Answer:

[tex] - 7 {x}^{2} + 7 {x}^{3} [/tex]

Step-by-step explanation:

[tex]( - 5 - 7 {x}^{2} ) + (5 + 7 {x}^{3} ) \\ = - 5 - 7 {x}^{2} + 5 + 7 {x}^{3} \\ = - 7 {x}^{2} + 7 {x}^{3} [/tex]