Question 626022
Let width of border=x So area of picture +border=120+168=288
But length=12+2x and width=10+2x
So (12+2x)*(10+2x)=288
120+44x+4x^2=288
4x^2+44x-168=0
x^2+11x-42=0
(x+14)(x-3)=0  x=3  (cant be -14