This problem is a word problem that requires algebra notation, actually, we are meant to convert this word problem to mathematical expression then solve.
We proceed in a stepwise manner
let say what I have is x
1. Subtract 5 from me
(x-5)
2. Then add 2
(x-5)+2
3. If you subtract 10
(x-5)+2-10
4. And then add 3
(x-5)+2-10+3
5. you get 15
(x-5)+2-10+3=15
what am I is the question we need to answer, we do this by solving for x