Respuesta :

Answer: They are not equal expressions

Since this asks to solve by substitution, I will substitute with the number 2:

5n + 9 + n

5(2) + 9 + (2)

10 + 9 + (2)

21

-

3(2n + 9)

3(2(2) + 9)

3(4 + 9)

3(4 + 9)

39

The answer is no, because 21 ≠ 39