Which expression is equivalent to 2 (3g-4) - 8 (g+3)

Since you don't have answer choices, I'll just assume you're trying to simply 2 (3g-4) - 8 (g+3).

First you want to distribute the two to what is inside the parentheses and the 8 to what is inside it's parentheses:

(3g*2 - 4*2) - (8*g + 8*3)

(6g - 8) - (8g + 24)

Then, distribute the negative to the (8g+24) to get rid of the parentheses. Most people forget this part and that leads to errors!

6g - 8 - 8g - 24

Finally, simplify:

-2g - 32

The expression is equivalent to - 2g-32.