I don’t know what to do and the steps for this

to simplify it, we need to combine like terms. 8 and 15 are like, and 5x and 2x are like. so we rearrange it: 8+15-5x-2x
and now we simplify: 23-7x
First of all we will collect like terms by saying 8+15-5x-2x
Threfore the final answer is 22-7x