What is 2x-4. I really don't understand

2 * - 4 = - 8

Step-by-step explanation:

2 * - 4 = - 8

It is just like multiplying two numbers like ... 2 * 4 = 8

You must need to know that:

+a * - b = - c

-a * - b = + c

+a * + b = + c

In your question;

+a * - b = - c

a = 2

b = - 4

c = - 8

therefore:

2 * - 4 = - 8