Explain how you know whether to add or subtract when you use the distributive property to multiply

Here is an example 8(3x+2) first you would multiply 8 times 3x and you would get 24x, and then you would multiply 8 times 2 and you get 16 so your final answer is 24x+16

I know when to add or subtract because + means add and - means subtract.
hope it helped.