Answer:
2 inches
Explanation:
If x is the width of the frame, then the overall dimensions are ...
(50 +2x) by (60 +2x)
so the area is ...
3456 = (50 +2x)(60+2x)
x^2 +55x -114 = 0 . . . . . . . divide by 4, subtract the left side
(x +57)(x -2) = 0 . . . . . . . . . factor
Solutions to this are x=2 and x=57 (extraneous).
The width of the frame is 2 inches.