Respuesta :
[tex]p = 2l + 2w[/tex]
P=Perimeter
L=Length
W=Width
Hints given are P= 76, L=20 so 2L=40
76=40+2w
76-40=2w
36=2w
18=w
The formula of a perimeter of a rectangle:
P = 2(w + l)
We have P = 76 cm and l = 20 cm.
Substitute:
2(w + 20) = 76 use distributive property
(2)(w) + (2)(20) = 76
2w + 40 = 76 subtract 40 from both sides
2w = 36 divide both sies by 2
w = 18