fill in the area of each small square and then add the results together to find the indicated product.(x + 3) (x +5)

Inside of box is :
[tex]\begin{gathered} x\times x \\ 5\times x \\ 3\times x \\ 5\times3 \end{gathered}[/tex]So the product is:
[tex]\begin{gathered} (x\times x)+(5\times x)+(3\times x)+(5\times3) \\ x^2+5x+3x+15 \\ x^2+8x+15 \end{gathered}[/tex]