Respuesta :

l = 15 w= 12

Step-by-step explanation:

P=2l+2w

l=w+3

* 42 =2(w+3)+2w *

Finding the l + w:

42= *2w + 6 + *2w

42 = 4w + 6

-6 + 42 = 4w + 6 -6

48 = 4w

48/4 = w

12 = w

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l = w + 3

l = 12 + 3

l = 15