Perimeter of a frame will be likened to as the perimeter of a rectangle:
This formula is Perimeter=2(length + width)
Perimeter:
[tex]\begin{gathered} =2\left\lbrace (7x^2+3x-3)+(5x^3+4x^2)\right\rbrace \\ =2\left\lbrace 5x^3+(7x^2+4x^2)+3x-3\right\rbrace \\ =2\left\lbrace 5x^3+11x^2+3x-3\right\rbrace \\ =10x^3+22x^2+6x-6 \end{gathered}[/tex]Thus, the perimeter expression for the photo frame is:
[tex]\text{Perimeter}=10x^3+22x^2+6x-6[/tex]