Use the FOIL method to multiply these terms. Multiply the first, outside, inside, and last terms:
(5x - 4)(2x - 5)
(5x)(2x) + (5x)(-5) + (-4)(2x) + (-4)(-5)
10x² - 25x - 8x + 20
10x² - 33x + 20
The area of the rectangle should be 10x² - 33x + 20.
You could say 84/2, 126/3, or even 168/4
(2x100) (3x10) (2x1) / (4x1)