If x is the uniform width of the frame, then the dimensions of the larger rectangle are (10 + 2x) and (32 + 2x). To find "x", you need to solve the "area" equation (10 + 2x)*(32 + 2x) = 504. You can solve it by any method you want/ you know. I will solve it MENTALLY by my own method: I will factor (mentally) 504 into the product of two factors that differ in 32-10 = 22: 504 = 14*36. Hence, 10 + 2x = 14 and 2x = 14 - 10 = 4. Then x = 2.