To solve this you need to use the distributive property
Distribute each of the first two terms into the second two terms
4x times 5x is 20x^2
4x times -2 is -8x
-1 times 5x is -5x
-1 times -2 is 2
Put it all together and you get:
20x^2-8x-5x+2
Combine the -8x and -5x to get -13x
so your final answer is
20x^2-13x+2