The distribuitve property is fairly simple. In your case, you want this equation to have only 2 factors. So all you have to do is multiply these numbrers together. 5 x 600 = 3000. 5x400 = 2000. So if you rewrite the equation, you will get 3000 + 2000 because 3000 is equivalent to 5 x 600. 2000 is equivalent to 5x400.
Your answer is 3000 + 2000.
I hope this helped :)