Respuesta :

evelyndennis2funmi

Answer:

21x + 28

Step-by-step explanation:

open the bracket

=21x + 4

parker0424

Answer:

well there might me an answer either u can put 21x +28 or 14x, but go with 21x + 28

Step-by-step explanation:

you multiply 3x time 7 and 4 times 7 since u cant add 3x plus 4 and to separate it to get a simpler expression