Answer
$x = 2.426$
Work Step by Step
The area of the photo will be half of the area of the entire ad. The area of the photo is $35$ $in^2$ The area of the entire ad must be $70$ $in^2$. For the entire ad, the length is $7+x$ and the width is $5+x$ . The area equation is shown below
$(7+x)(5+x) = 70$
$x^2 + 12x + 35= 70$
$x^2 + 12x - 35 = 0$
Solve the equation using any method. Here we will use the quadratic formula
$x = \frac{{-12 ± \sqrt {144+140}}}{2}$
We must take only the positive solution as that is reasonable.
$x = 2.426$
