Respuesta :

Answer:

3x + 1

Step-by-step explanation:

let the unknown number be x

x * 3 + 1  ...........here we multiplied by 3 and added 1

3x + 1

Answer:

[tex]x(3)+1[/tex]

Step-by-step explanation:

As we don't know what we are multiplying, simply use x to replace that factor. we'll receive the equation  x(3)+1.