doy1
contestada

a portrait has dimensions of 30 inches by 40 inches and is surrounded by a frame of uniform width. if the total area (portrait plus frame) is 1496 square inches, find the width of the frame.

Respuesta :

Let w be the width of the frame. Then:
(2w+30)(2w+40)=1496
4w²+140w-296=0
w²+35w-74=0
(w+37)(w-2)=0
w=2
The width of the frame is 2 in.
☺☺☺☺