Answer:
[tex]5x^{2} -18x-8[/tex]
Step-by-step explanation:
The formula for area of a rectange is lw, where l is length and w is width. Since x-4 and 5x+2 are the sides, we can multiply them together to give us the area. We do (x-4)(5x+2). We use the FOIL method (First Outside Inside Last) and get 5x^2-18x-8.