Respuesta :

Answer:

f < 4

Step-by-step explanation:

3f + 9 < 21

21 - 9 = 12

12 / 3 = 4

Answer:

[tex]\boxed {f < 4}[/tex]

Step-by-step explanation:

Solve the following inequality:

[tex]3f + 9 < 21[/tex]

-Subtract [tex]9[/tex] on both sides:

[tex]3f + 9 - 9 < 21 - 9[/tex]

[tex]3f < 12[/tex]

-Divide both sides by [tex]3[/tex]:

[tex]\frac{3f}{3} < \frac{12}{3}[/tex]

[tex]\boxed {f < 4}[/tex]