Scrapbook is 15 inches by 15 inches

Question

You are making a scrapbook with pages that are 15 inches. On one page, you want to put two 4 inch by 6 inch photographs, each with blue boarders of equal width,as shown. What is the widest border you can use if you want at least 1 inch of space on well sides of the photos

Answer 1

if the width of the border is x and you place the photos side by side with the 4 inch dimension horizontal and 6 inch vertical, then we have two possibilities.
 
For the horizontal, 4x + 8 + 3 = 15
4x = 4
x = 1 inch
 
For the vertical, 2x + 6 + 2 = 15
2x = 7
x = 7/2
 
Therefore 1 inch is the widest border possible