Respuesta :

The first thing we must do for this case is to define a variable.
 We have then:
 n: unknown number.
 We write the algebraic expression:
 13 - 4n
 For n = 3 we have:
 13 - 4 (3) = 13 - 12 = 1
 Answer:
 
An expression that represents this phrase is:
 
13 - 4n
 
its value if n = 3 is:
 
1

Answer:

1

Step-by-step explanation: 13-4n ; when n = 3 the value is 1