I have no idea what the x is doing, so imma take it out.
First we multiply 2 x a and 2 x 5.
Because we can't directly multiply a variable, we will write 2a.
2a+10+(a+5).
We can remove the parenthesis now.
2a+10+a+5.
Now we add. a has an invisible 1, so we make the 1 visible.
2a+1a+15
3a+15
That's all we can do with the problem.
---
sorry if this doesn't help