Question

-2(x + 5) = -2x - 10 is an example of which property?

Answer 1

you are distributing the -2 in

Answer 2

$$\Huge -2(x + 5) = -2x - 10$$
$$\Huge a(b+c)=ab+ac$$

Answer 3

Note that -2 is distributed as a multiplier of each term of the sum x +5.