Question

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 2000 square​ inches, find the width of the frame.

Answer 1

Let
w----> width of the frame

we know that

[the total area​ (portrait plus​ frame)=(30+2w)*(40+2w)
2000=(30+2w)*(40+2w)
2000=1200+60w+80w+4w²
4w²+140w+1200-2000=0
4w²+140w-800=0

using a graph tool------> to resolve the second order equation
see the attached figure

the solution is
w=5 in

the answer is
w=5 in