Answer:
x^2+6x+8
Explanation:
The initial way to represent the area of the entire rectangle is (x+2)*(x+4).
With this, we can multiply the two together using the FOIL method (First, Outside, Inside, Last).
x*x=x^2
x*4=4x
2*x=2x
2*4=8
Add these together, and you get your final answer:
x^2+6x+8