Respuesta :

length(l)= 2w+6
width(w)= w

Perimeter(P)= 60 inches= 2w+2l (divide each side by 2 to simplify)
P=30 in= w+l

Plug in expression for "l" to be able to add like terms.
P=30=w+l
P=30=w+(2w+6)
P= 30= 3w+6
P= 24= 3w
w= 8 inches

Answer: 
The width of the rectangle is 8 inches.