Respuesta :

To find this number, let's represent the unknown amount of students with the variable x:

356 + 365 + x = 977

721 + x = 977

x = 256

There are 256 students in ninth grade.

Hello,

Équation : 356 + 365 + x = 977
→ 731 + x = 977
→ x = 977 - 731 = ....

Bye :)