Mind my hand writing but i’m not sure what sign to put the “-“ or the “+” ?

hello!

so the answer that you put there is actually wrong and i'll tell you why and how to do it

so since you are adding the two:

-8x + 9x = x (so you got this part right)

-12 + 4 = -8 (this is where you got it wrong, -12 added 4 goes up in value to -8)

so the final answer is x - 8

i hope this helped and have a nice day!

4444444444444 i think