we know that
the area of the photo is ------> 4*2-----> 8 in²
the area of entire ad is 8*2-----------> 16 in²
and
the area of entire ad is--------> (4+x)*(2+x)-------> 8+4x+2x+x²
x²+6x+8=16------> x²+6x-8=0
using a graph tool------------> to resolve the second order equation
see the attached figure
the solution is
x=1.12 in
the answer is
x=1.12 in
