Respuesta :

Uchixie

Answer:

4m-12

Step-by-step explanation:

since the perimeter of a square is the addition of all four equal sides, therefore:-

P=(m-3)+(m-3)+(m-3)+(m-3)

P=m-3+m-3+m-3+m-3

collect like terms

P=m+m+m+m-3-3-3-3

P=4m-12.