Answer:
15
Explanation:
For each time I see x, I replaced it with 7 because I know that x is equal to 7.
I only see one x so I am only replacing that one x so instead of x + 8, I get 7 + 8 and you could split 8 into 5 + 3 and split 7 into 5 + 2.
5 plus 5 is 10. If you are having trouble adding the numbers you could put up 5 fingers first and then add one finger up one by one to still the number 10. Now that just leaves you with 3 + 2.
You could first put up 3 fingers and then add two more to get a total of 5 fingers.
At last, you could just add 10 + 5 to get 15 in total.
Hope this works you!!!